A cold spell isn't new for the 27-year-old Pena, one of the streakier players on the Tigers. He had similar struggles early last season before heating up in the second half to finish with a team-high 27 home runs. The longer the Tigers waited, however, the deeper the slump grew. Moreover, the offensive frustration seemed to begin affecting him in the field. His three errors this season were halfway toward last season's total, with two errors coming in recent weeks.
Pena's manager and teammates alike said that the mental frustration was clearly wearing on him.
"My feeling is he needs to regroup," said Alan Trammell, who made the decision on Monday night. "Right now it's very difficult for him. He didn't show signs of it. At some point you just think that's the best thing, to get away from this, go down there and find it."
Rondell White could relate from his younger days, in Montreal.
"I just remember thinking [every at-bat was] life or death," said White, "and you really can't do that. Every at-bat, you really want to be good, and then you put too much pressure on yourself. He's going to be all right."
Pena, who was told of the move on Tuesday afternoon, has 72 hours to report to the Mud Hens, who are currently on the road at Buffalo and don't return home until June 7. The move does not affect the one-year, $2,575,000 contract he signed last December.
"We think he's certainly going to be back," Trammell said. "And now it's up to Carlos how soon [he returns]."
The other end of Pena's struggles is that they accelerated Shelton's return to the big leagues. The Tigers had moved Shelton to Toledo at season's start to play regularly at first base after he'd garnered just 46 at-bats in Detroit last season.
Shelton showed no signs of rust, batting .331 with eight home runs and 39 RBIs in 48 games for the Mud Hens through Monday. His 19 doubles and 103 total bases lead the International League.
A few days earlier, Shelton said that he hadn't been reading speculation about the Tigers weighing whether to call him up.
"It was a complete surprise to me," said Shelton. "I was expecting to stay down there, get some at-bats and just continue playing. It was a complete surprise, but I'm happy to be here."
How regular his at-bats will be in Detroit wasn't quite certain as of Tuesday. Dmitri Young started the last two games in Baltimore at first base and was back there on Tuesday. Shelton batted seventh, as designated hitter, but the condition of Carlos Guillen's knee could force the All-Star shortstop to stay in that spot for a while.
"A lot of it has to do with Guillen," Trammell said.