MINNEAPOLIS -- Rookie second baseman Alexi Casilla has had a turbulent half-season since he's been up with the Twins.

Casilla has found himself sitting on the bench frequently as of late because the Twins want him to watch the game and learn how to slow himself down. He's working with hitting coach Joe Vavra to shorten his swing, and he's been practicing in the infield to work on his defensive skills.

So Casilla would likely relish a chance to start when it comes around.

Well, that chance came and went on Sunday morning. Casilla was penciled into manager Ron Gardenhire's original lineup, but was then scratched when he showed up at 11 a.m. CT for the 1 p.m. game.

Casilla explained that he recently got a new cell phone, and he set his alarm for early this morning, but it didn't go off.

"You have to be responsible. I would make sure that I had 16 different ways to wake me up for a day game. You can't take any chances at all," Gardenhire said. "All we ask is that you're on time around here and he wasn't on time, he was late. That's the bottom line. If you're going to be late, we ask that you call. He didn't call either."

Casilla arrived just before 11 a.m., when the Twins were scheduled to hit in the cage, so he will not be fined.

"It's going to happen, people make mistakes, but with rookies it should happen less than often than with veterans. You're more in the spotlight up here as a rookie than guys who have been around," Gardenhire said. "I'm not going to take his money, but I think missing a ballgame might hurt him more than losing his money."

Gardenhire put Brian Buscher into the lineup at third and moved Luis Rodriguez to second base. Jason Tyner replaced Casilla in the leadoff spot, playing left field.

Regrets: Justin Morneau at least partly blames his participation in the Home Run Derby for his second half offensive slump, and his manager does not disagree.

Morneau is batting just .254 in the second half, compared to .295 in the first half. He's only hit six home runs post-All Star break, whereas he had 24 before.

"I was not a big proponent of it anyway," Gardenhire said of the Derby. "We never tell players you can't do this or you can't do that. The league asked him to do it, and he said he'd like to do it. I've never been fond of that kind of thing. I enjoy watching it, but it's something that he chose to do, and if he chooses not to do it anymore, that'd be fine."

Gardenhire was skeptical that the contest could actually physically hamper Morneau, but agreed that it may have taken its toll mentally.

"If he says that hurt him, who knows," Gardenhire said. "It's [batting practice], it's just like taking [batting practice] every day but swinging harder. Maybe it's in his mind. Maybe he's trying to figure out why, and that's something that crops up. But that's a good thing, him saying he doesn't want to do that anymore."

Right on schedule: After throwing a bullpen session on Saturday and feeling no pain in his right groin, Carlos Silva came into Gardenhire's office on Sunday morning to plead his case for making his scheduled start on Tuesday.

Silva argued that he was pain free, and Gardenhire argued that he didn't want him to re-injure the groin that caused him to exit his previous start early. Silva came out victorious and will make his start against the Rangers.

"He pleaded his case as hard as you can plead your case [Sunday] morning," Gardnehire said. "He says he feels great, and he'd like to pitch Tuesday. I explained our side of it and what I'm leary of, but he says he feels great with no problems."

Falling short: Class A Beloit lost to West Michigan, 11-5, in Game 5 of the Midwest League championship series to end its season.

The Snappers committed six errors in the loss, five in the fifth inning alone. The errors led to six unearned runs for the Whitecaps.

Catcher Gregory Yersich tripled in three runs in the five-run third inning for Beloit. But West Michigan's bullpen came in to pitch seven scoreless innings of relief.

Up next: The Twins start a three-game series with the Rangers on Monday at 7:10 p.m. CT in the Metrodome. Kevin Slowey (3-0, 5.44 ERA) will get the start in the opener for the Twins. Edinson Volquez (2-1, 4.24) takes the mound for the Rangers.