Rosenthal: Delayed arrival for budding stars in MLB

Young stars are delayed getting to the majors because of financial considerations, but this talented batch should be there shortly.

Francisco Lindor could force the Indians into making a move at shortstop.

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Baseball is again a young man’s game in the testing era, creating entirely new personnel strategies. In-season call-ups can be as pivotal as trade acquisitions, as evidenced by the successes of Rays outfielder Wil Myers and Pirates righty Gerrit Cole in 2013.

By now, you know the drill -- teams often wait to promote their top prospects to gain an extra year of control over them before free agency and/or to prevent the players from gaining an extra year of salary arbitration.

Some youngsters are starting to trickle into the majors -- Astros outfielder George Springer, Blue Jays righty Marcus Stroman, Angels first baseman C.J. Cron. The true influx will come in early to mid-June, when teams no longer will fear call-ups qualifying for “Super Two” arbitration status.

I dislike the system, which often discourages teams -- for unspoken financial reasons -- from using their best 25 players. And frankly, such roster manipulation is becoming more difficult to defend with clubs signing many players long-term before they even reach arbitration.

For now, though, the service-time games continue. Here is a list of players that we should see -- and need to see -- before season’s end. Before you tweet, “What about Johnny Highheat? What about Jimmy Godeep?” understand that the list is by no means complete.

*Gregory Polanco, Pirates: The main argument against the Pirates promoting Polanco to play right field is that he has only 422 plate appearances above Class A. Andrew McCutchen had 1,466 before reaching the majors, Starling Marte 1,003.

Gregory Polanco

Kim Klement / USA TODAY Sports

Here’s the problem: The Pirates declined to address their right-field hole in the offseason, presumably because they did not want to block Polanco, who was in the process of becoming MVP of the Dominican Winter League.

Polanco, 22, has gone on to bat .397 with a 1.070 OPS in his first full season at Triple A, though he recently went through a trying stretch, striking out 17 times in 14 games. Meanwhile, the Pirates rank 25th in the majors in OPS from their right fielders, and the team is fourth in the NL Central, 9½ games out of first place.

“Our won-loss record has no impact on Gregory Polanco’s readiness to thrive at the major-league level,” general manager Neal Huntington says.

OK, and the Pirates were rewarded for their patience with Cole, Marte and McCutchen. But if Polanco stays hot, it will be difficult for the team to justify keeping him at Triple A past mid-June, much less nearly the entire season.

Polanco is too good. And too much is at stake.

*Oscar Taveras, Cardinals: Unlike the Pirates, the Cardinals do not seem resistant to the idea of promoting Taveras, their top outfield prospect. The problem is that they’re still looking at three other center fielders -- Peter Bourjos, Jon Jay and rookie Randal Grichuk.

Taveras, who turns 22 on June 19, isn’t going to replace Matt Holliday in left or Allen Craig in right -- and Craig isn’t going to return to first base with Matt Adams batting .328 with an .819 OPS.

Bourjos would be ideal in center if he could hit well enough to hold down the position -- the Cardinals’ corner-outfield defense is poor, so they need an above-average defender in center.

Taveras is batting .312 with an .878 OPS, but has played in only 28 games after appearing in 47 last season due to an ankle injury. If the Cardinals promote him, he would need to get the overwhelming majority of starts. And club officials are not ready to make such a call yet.

GM John Mozeliak told the St. Louis Post-Dispatch that the team wants Taveras to play "a lot" more in center before summoning him to the majors.

Trevor Bauer

David Richard / USA TODAY Sports

*Trevor Bauer/Francisco Lindor, Indians: The Indians are the Pirates of the AL, a team that has regressed after making a surprising postseason appearance a year ago.

Bauer, 23, almost certainly will rejoin the club soon -- he has made six quality starts between Triple A and Cleveland, throwing 94 to 98 mph, improving his fastball command while maturing and growing as a teammate.

Lindor, though, is even more intriguing.

Indians shortstop Asdrubal Cabrera, a potential free agent, is batting only .211 with a .604 OPS. Ideally, Cabrera would get hot, making it easier for the Indians to trade him. But Lindor, who at 20 is the youngest player in the Double A Eastern League by nearly a full year, could force the issue regardless.

Not only is Lindor batting .290 with a .817 OPS, he also is excelling defensively and continuing to impress the Indians with his work ethic, professionalism and leadership. He and second baseman Jason Kipnis eventually will form a terrific double-play combination, one under club control through at least 2019.

*Eddie Butler/Jonathan Gray, Rockies: The Rockies’ rotation seems forever in turmoil, even when the team is playing well. This season is no different -- lefty Brett Anderson (finger) and righty Tyler Chatwood (elbow) are out until at least June, righty Jhoulys Chacin just returned from a right shoulder strain and lefty Franklin Morales isn’t inspiring much confidence.

The difference now is that the Rockies appear deeper in starting pitching than in the past -- emphasis on “appear.” Butler and Gray, the team’s top two pitching prospects, are progressing nicely at Double A. But a pair of lefties at Triple A, Tyler Matzek and Christian Friedrich, likely would get chances first.

*Andrew Heaney, Marlins. Don’t look now, but the Rockies are the only NL team with a better run differential than the Marlins, who are tied for second with the Giants at plus-25.

The Marlins’ rotation, tied for sixth in the NL with a 3.40 ERA, is a huge part of the club’s success, as is the team’s sudden dominance at home -- the Fish are 15-5 at Marlins Park, 2-10 on the road.

That rotation, however, is all right-handed -- and Jacob Turner allowed six runs in four innings on Saturday against the Dodgers after missing a month with a strained right shoulder.

Heaney, a left-hander, is the team’s top prospect according to Baseball America. He’s off to an excellent start at Double A, with a 2.45 ERA, 33 strikeouts and eight walks in 33 innings.

Rafael Montero

Brad Penner-USA TODAY Sports / Brad Penner-USA TODAY Sports

*Noah Syndergaard/Rafael Montero, Mets: The Mets need more help in their bullpen than their rotation, and both Syndergaard and Montero are right-handed starters. Not to worry: Both pitchers figure to follow the Matt Harvey-Zack Wheeler plan if they continue to progress, arriving in June or July and helping round out the staff.

The promotion of Syndergaard would enable the Mets to move righty Jenrry Mejia to the bullpen, a move that would be necessary regardless, considering that Mejia threw only 52 innings last season.

Montero, meanwhile, repeats his delivery well enough to break in as a reliever, and still could compete for a spot in the rotation next spring.

*Maikel Franco, Phillies: Franco, a third baseman, can’t solve the Phillies’ biggest problem -- their bullpen, which rivals the Mets’ for the worst in the NL. The team, though, also ranks 27th in the majors in OPS at third, where Cody Asche does not appear to be the answer.

Franco, 21, got off to a horrid start at Triple A, but in his last 10 games has batted .326 with a .922 OPS. The Phillies, heavy on left-handed bats, would benefit from his right-handed presence.

“He’s good -- the last player I’m worried about,” general manager Ruben Amaro Jr. said, adding that Franco is not ready yet, but will be at some point -- presumably soon.

*Javier Baez, Cubs: If Baez were hitting at Triple A, the Cubs would face the same type of pressure to promote him as the Pirates face with Polanco. Instead, Baez is making it easy for the Cubs to keep him in the minors, even after hitting a combined 37 homers at Class A and AA last season.

Baez, 21, is inexplicably batting only .149 with a .543 OPS. If he’s disappointed over his failure to stick with the major-league club, he needs to get over it. The Cubs rank 24th in the majors in OPS at second base, the position that Baez likely will play at the start of his career, given the resurgence of shortstop Starlin Castro.

*Jonathan Singleton, Astros: Think maybe the Astros should have called up Springer last September for a taste of major-league experience?

Springer, 24, has batted only .191 with a .477 OPS since his debut on April 16, and the Astros are on pace for their fourth straight 100-loss season.

Singleton, who leads the Pacific Coast League with 10 homers, could provide a jolt at first base, where the Astros rank 28th in the majors in OPS. Right-hander Mike Foltynewicz also could be part of the second-half rescue plan -- he struck out 12 in six innings Monday, including his final six hitters.

*Archie Bradley, Diamondbacks: Even after recent improvement, the D-Backs’ rotation remains the worst in the majors. Bradley, who loomed as a potential solution, is on the disabled list with a mild flexor strain in his right elbow.

The D-Backs already have lost left-handed starter Patrick Corbin and right-handed reliever David Hernandez to Tommy John surgery. They obviously will handle Bradley with care, especially since they already are nearly out of contention.

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