"His slider is very good," Tigers pitching coach Jeff Jones said. "It's just what he needed, and his changeup is good, too. Bruce has three quality pitches."
Rondon began putting it together down the stretch last season, and ended up 1-2 with a 3.45 ERA and 30 strikeouts in 28 2/3 innings over 30 games. But a tender elbow knocked him out of the postseason, where Detroit could've used him in the late innings.
This spring, he's healthy and 30 pounds lighter at 245 pounds, and Tigers manager Brad Ausmus is looking at either Rondon or Joba Chamberlain to take the eighth-inning setup role before All-Star closer Joe Nathan.
So far, Rondon, who's scheduled to pitch Friday night against the New York Yankees, is mowing down batters in Grapefruit League games. He had two 1-2-3 innings with a save in his first two appearances before struggling a bit in his third outing, against Pittsburgh.
In that game, he gave up one run on two hits. He struck out three Pirates, however, and wouldn't have allowed a run had catcher Ramon Cabrera been able to snag a swing-and-miss in the dirt that allowed Omir Santos to reach first base. Santos would've been the third out.
Although he still gets strikeouts, Rondon no longer lives by them or the radar-gun sideshow that once defined him.
There was a day when 103 mph was more than enough for a pitcher. When Tigers Hall of Famer Al Kaline first faced Nolan Ryan's 100 mph heat, Kaline said he knew the end was near.
But pitcher-hitter confrontations have changed considerably in the 40 years since.
"The reason hitters hit that pitch now is because the strike zone is smaller," Kaline said.
Mr. Tiger displayed where the strike zone used to be by tapping me just below my chest. He then demonstrated where it is now by pointing a little above my belt.
"I tell (Justin) Verlander that he would've been unhittable in our era," Kaline said. "They'd throw us a high-strike fastball with two strikes and it was tough to touch.
"Now there is no high fastball called a strike."
And when hitters see the 100 mph strike that's called today, they're able to time it.
"If you see it consistently or more often," Tigers catching great and Erie manager Lance Parrish said, "it's not that difficult to make the adjustment.
"If you would see 110 (mph) enough, you'd get your timing."
So while there continues to be a rush connected to watching Rondon throw 103 mph heat, it's much more telling of the outcome when his change and slider are sharp.
Rondon also has toned his body as surely as his pitching repertoire. Tigers strength and conditioning trainer Javair Gillett designed a strict training regimen that Rondon followed during the offseason, and he cut out all fried foods.
Did he hire a chef to prepare meals?
"No," Rondon said with a big smile. "It was my momma who did my cooking."
His paunch is gone.
"I think losing the weight will do nothing but help him," Jones said. "He feels good about how he looks."
Rondon, speaking through team publicist and translator Aileen Villarreal, nodded and agreed with Jones.
"Si" Rondon said with a smile. "I feel great, and I feel real motivated to do even more."