TAMPA, Fla. -- The Rays will continue to use caution, pushing back ace Scott Kazmir's Grapefruit League debut by several days. Kazmir, who suffered an elbow strain in an intrasquad game on Feb. 25, was slated to pitch in Sunday's game against Detroit.

"We just want to try to build up a little bit more arm strength before we put him out there," manager Joe Maddon said on Saturday morning. "He's fine."

The lefty, who threw to live batters Thursday and had a long-toss session Friday, reported on Friday morning that he felt fine.

Maddon said the delay shouldn't be considered a setback, and is confident Kazmir will pitch in the next few days.

"He's going to play catch and go back on the mound again, and then when I'm satisfied, we'll put him into the game," Maddon said.

With the scratch, Maddon confirmed that No. 2 starter James Shields will get the ball for Opening Day on March 31 in Baltimore.

Maddon said if Sunday's game was a regular season or playoff game, Kazmir would be deemed healthy enough to throw, but given the situation, the Rays want to err on the safe side.

"It's hard. There's really nothing wrong, except I wanted his arm to be a little bit stronger," Maddon said.

Last season, Kazmir led the American League in strikeouts and finished with a 3.84 ERA. The Rays signed the left-hander to a one-year, $3.785 million contract on Jan. 18.