PHOENIX -- The overhaul of the Diamondbacks' starting rotation has begun.
Josh Collmenter will replace Randall Delgado the next turn through, making his first start since 2012 against the New York Mets on Monday. Bronson Arroyo will go again Tuesday, getting an extra day of rest, and Delgado will move to the bullpen.
"Looking at our options, that seems the smartest way to go," D-backs manager Kirk Gibson said. "We're going to go with this and see how it works."
The D-backs' starters entered Friday's 6-0 loss to the Dodgers with a 6.57 ERA, the worst in the National League and 29th in the majors, one of the reasons Arizona signed veteran left-hander Randy Wolf to a minor league deal Friday morning.
Delgado, projected to pitch out of the bullpen when spring training began, joined the rotation after Patrick Corbin underwent season-ending Tommy John surgery but was ineffective in two starts. Delgado gave up nine earned runs in 7 1/3 innings and is 0-1 with a 10.13 ERA in three outings, including a short relief appearance in Australia.
Collmenter found a niche as a long reliever last season, when he led NL relievers with 92 innings, including 29 extra innings. But starting the game well is job one, especially for the D-backs (4-9), who have two quality starts, tied for 27th in the majors. Collmenter threw 53 pitches in four scoreless innings of relief Tuesday in San Francisco.
"You know we need innings out of guys, and he gives us a chance to win a ballgame," D-backs manager Kirk Gibson said. "He did it in relief last year, and he did it in 2011."
Collmenter was 10-10 with a 3.38 in 2011, when he joined the team in April and finished fifth in the NL Rookie of the Year balloting.
"He has a special arm. He's just one of those guys," Gibson said.
Wade Miley, who is to start Saturday, is 2-1 with a 4.05 ERA this season, the only starter with an ERA under 4.82. Brandon McCarthy gave up six runs in seven-plus innings against the Dodgers on Friday and is 0-2 with a 7.78 ERA. He has given up five home runs, tied with the New York Yankees' CC Sabathia for the most in the majors. Trevor Cahill, who is to start Sunday, is 0-3 with a 7.90 ERA in three starts. Arroyo, who was delayed in spring training because of a back issue, is 1-0 with a 4.82 ERA.
Of making the rotation change, general manager Kevin Towers said: "You watch them start. When you've had enough, you've had enough. You want to have several options to choose from, or not be in a position where you feel like you have to rush an Archie Bradley until you feel he is ready."
Wolf is expected to join Class AAA Reno, and Towers said Wolf could be an option if other rotation retooling is done. Bradley and right-handers Bo Schultz, Mike Bolsinger, Charles Brewer and Alex Sanabia are in Reno's rotation.
"We wanted to at least have insurance and to see how things go here," Towers said of signing Wolf to a contract that is worth $1 million. "He is a fierce competitor, good athlete. Controls the running game. Swings the bat very, very well. It's another option for us if we decided to make another move or decision when it comes to one of our starters."
Wolf, 37, underwent Tommy John surgery in October 2012 and did not pitch last season but showed well as a nonroster invitee in the Seattle Mariners' camp this spring after a signing a contract that would be worth $1 million if he made the team. The Mariners told Wolf in late spring that he would join a rotation that was to start the season without injured Taijuan Walker and Hishashi Iwakuma. The Mariners asked Wolf to sign a contact that included a clause that said he could be demoted or released after 45 days and get only a pro-rated portion of the salary. He declined and became a free agent.
Wolf is 132-117 in 14 major league seasons, winning 37 games from 2009-11 with the Dodgers and Brewers.
Dodgers first baseman Adrian Gonzalez has done some of his best work against the Diamondbacks. After hitting a two-run home run and driving in five runs, Gonzalez leads active major leaguers with 25 homers and 82 RBIs against the D-backs. "You can't focus on one thing, because it hasn't been over a two-year period," Gonzalez said of his success. "It's been over a longer period. There have been different catchers, different pitchers, different coaching staffs. It has nothing to do with something you can pinpoint."
12 -- consecutive shutout innings by Hyun-Jin Ryu against the D-backs this season, seven on Friday and five in a 7-5 victory in Sydney, Australia, on March 23.
-- Miguel Montero got the D-backs' only two hits off Dodgers Ryu, a single to center field and a single to left. He has four hits in his last eight at-bats.
-- After giving four early runs, McCarthy retired 11 straight batters from the third inning into the seventh inning before the Dodgers opened the eighth with three straight hits off him. "I'm actually throwing not terribly," an obviously frustrated McCarthy said. "I don't know what the hell is going on. It's a morally defeating game, especially to kind of have it figured out in the middle innings. It's just a few pitches here or there that have gone wrong that have really hurt me." McCarthy has given up five, six and six runs in his three outings, the first time in his career he has given up at least five in three straight appearances.
-- A.J. Pollock was the only other baserunner against the Dodgers, walking against Ryu in the first inning and against reliever Jamey Wright in the eighth. The D-backs did not get a runner past first base.
-- Cody Ross is to play for Class AAA Reno in Tucson the next several days, and Towers said it is possible Ross could join the D-backs by the end of this homestand that concludes Wednesday against the New York Mets or for the road trip that beings Friday in Los Angeles against the Dodgers.
The D-backs are last in the majors with a minus-27 run differential, and the Astros (4-7) are the only other team with a run differential in double figures. "You want to work ahead, anybody knows that," Gibson said. "We haven't done a lot of that this year."
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