Catcher Joe Mauer also went to the DL, as expected. Mauer is recovering from inflammation in his lower back, which will keep him out for at least the next few weeks.

Left-hander Francisco Liriano will instead take the mound for Minnesota on Monday against Seattle, but pitching coach Rick Anderson said the move — made retroactively to last Saturday, making Baker eligible to return April 12 — was precautionary and would only cause him to miss the first turn in the rotation.

Baker developed some soreness Wednesday after throwing in a minor league game, but he said he wasn't concerned.

"The decision technically wasn't up to me. I could definitely have pitched," said Baker, who signed a $15.25 million, four-year contract last month. "I'm an investment. They want to protect their investment."

This would have been the first opening day start of his career.

"It stinks," Baker said. "The timing is just not great. I would love to pitch on opening day, but that's not the best thing for our team. I'll take a couple of days off from throwing and then pick it up from there."

Knuckleballer R.A. Dickey will replace Baker in the rotation, following Nick Blackburn, Kevin Slowey and Glen Perkins. Dickey was competing with rookies Brian Duensing and Phil Humber for two spots in the bullpen, but Baker's injury allows the Twins to postpone their choice. Humber can't be sent to the minors without clearing waivers, complicating the decision.

Dickey, who made his big league debut in 2001 with Texas and has logged more than 378 innings in the majors since, is 2-2 this spring with a 2.04 ERA, four walks and 18 strikeouts in 17 2-3 innings.

"He earned it," Anderson said. "He worked hard."

The Twins also put right-hander Boof Bonser on the DL Thursday. Bonser had shoulder surgery and is expected to miss the season.