PEORIA, Ariz. -- The Padres granted righty reliever Casey Janssen his release on Thursday, adding a small bit of clarity to a crowded bullpen battle.
Janssen, who had signed a Minor League deal with an invitation to Spring Training, allowed four earned runs on 12 hits in seven Cactus League innings.
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Entering camp, the 34-year-old right-hander appeared to be a favorite for a spot on the Opening Day roster. But the addition of Matt Thornton, along with the club's decision to keep Brandon Maurer in a relief role -- after experimenting with him as a starter -- put a dent in Janssen's chances. He exercised the out clause in his contract when the club informed him he wasn't in the Opening Day roster plans.
"Maurer goes back to the bullpen, the emergence of Thornton, a lot of these young arms -- he was getting further and further behind the 8-ball," Padres manager Andy Green said of Janssen. "Out of respect to someone like himself, who has done so much in the game and been so successful, rather than hold him until his last day of his out clause, we allowed him his release today."
As for the rest of the 'pen, the race remains wide open, and Green expects it to come down to the final day or two of Spring Training.
Fernando Rodney, Carlos Villanueva and Maurer are the only locks at this point, with Drew Pomeranz joining them if he doesn't make the rotation. Nick Vincent and Kevin Quackenbush are also favorites for the 'pen, potentially leaving only one or two spots available for the nine other relievers still on the big league roster.
"There's a lot of guys doing really well," Green said. "Sometimes you've just got to give yourself as much time to factor into the equation things that change in the last few days -- those health-related things that always emerge."
Other notes from Thursday:
McGwire will manage split-squad games

Bench coach Mark McGwire has been given managerial duties for the split Padres squad that will remain in Arizona this weekend, while the other half heads to Mexico City to face the Astros.
McGwire, who had spent five seasons as a hitting coach with St. Louis and the Dodgers, is in his first season as bench coach. He missed three weeks earlier in camp to tend to his family while his wife dealt with an undisclosed medical issue.
Jankowski on the mend

Center fielder Travis Jankowski, who suffered a bruised left ankle after being hit by a pitch on Tuesday, remains on schedule to make the trip to Mexico City. The club will depart Friday and return Sunday night.
First baseman Brett Wallace, meanwhile, continued to get game action on a back field at Padres camp, as he is recovering from a sore left foot. Wallace hasn't played since March 13.
Perdomo sees success after adding split-finger
Righty reliever Luis Perdomo escaped a bases-loaded, one-out jam in the fifth inning of Thursday's game against the D-backs by getting Tuffy Gosewisch and Nick Ahmed to strike out swinging. Perdomo -- a Rule 5 Draft pick who has never pitched above Class A -- is fighting for a spot in the bullpen and has struggled mightily adjusting to big league hitters.
But the club's No. 12 prospect may have found a new weapon. Pitching coach Darren Balsley helped teach Perdomo a split-finger fastball earlier this week, and Perdomo used it successfully a couple times on Thursday -- including the whiff of Gosewisch.
"Three days ago, I had five pitching coaches coming in raving about his split-finger," Green said. "So classic cynic, I said I want to see it out on the field. I saw it, and it was biting hard."