"We needed an arm," Ausmus said of the move. "The bullpen's shot."
After 346 Minor League appearances over 13 seasons, Molleken will take it. The native Canadian, a 15th-round pick of the Pirates 13 years ago, has been pitching in Triple-A for five organizations since 2011, with a couple years mixed in pitching for the Nippon Ham Fighters of Japan's Pacific League.
This season, Molleken is 1-3 with a 3.76 ERA in 23 appearances (four starts) for the Mud Hens. Opposing batters are hitting .224 off him in 38 1/3 innings. He has battled command, walking 25 against 34 strikeouts. Ten of those walks have come over his past three outings, including two starts, totaling 7 1/3 innings.
To make room for Molleken on the 25- and 40-man rosters, the Tigers designated third baseman Casey McGehee for assignment Monday, two days after he was called up as an extra bat. His pinch-hit appearance and groundout in Saturday's 16-5 loss to the Royals was his only at-bat.
It was a quick stint for a veteran hitter who loomed as insurance for the Tigers in case of injuries at first or third base. McGehee could still end up back at Toledo, where he had been all season until this weekend, but he'd have to clear waivers and then accept an outright assignment to the Mud Hens. With six full seasons in the Majors, the 33-year-old McGehee has the right to decline an assignment and become a free agent, which might happen if he senses a better path to the big leagues elsewhere.
The swap means the bench is again down to three position players, with utilitymen Andrew Romine and Mike Aviles joining backup catcher Jarrod Saltalamacchia in the dugout. Detroit's roster makeup has been this way for most of June.
The Tigers will most likely go to eight relievers in the next few days, once they decide on a starter to take Matt Boyd's rotation spot for Thursday's series finale against the Mariners. If it's Anibal Sanchez, the Tigers don't necessarily have to make a roster move. If it's Daniel Norris, Detroit would most likely send down a reliever to bring up Norris from Toledo.
In other roster moves, the Tigers transferred right-handed reliever Drew VerHagen from the 15- to 60-day DL, a sign that the Thoracic outlet syndrome in his shoulder is going to take a while to address. VerHagen had been on the 15-day DL retroactive to May 23. The move opens a spot on Detroit's 40-man roster.
Jason Beck has covered the Tigers for MLB.com since 2002. Read Beck's Blog, follow him on Twitter @beckjason and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.