MINNEAPOLIS -- The Twins will be without infielder Jeff Cirillo for at least a few days as he deals with soreness in his left knee.

An MRI was taken of Cirillo's left knee on Tuesday and an old meniscus tear was found. Twins general manager Terry Ryan said doctors felt it was an old problem that flared up, and Cirillo was given a cortisone shot to try and calm the problem.

Cirillo first started feeling the soreness in his knee on Sunday, but it was during Monday's game against the Orioles when he was running the bases that the soreness became too much to play through.

Twins manager Ron Gardenhire pinch-hit for Cirillo in the sixth inning after he was walked by Orioles left-hander John Parrish. Prior to the at-bat, Cirillo had told the manager that he likely wouldn't be able to run the bases due to his knee.

And when Gardenhire saw the infielder on Tuesday, he knew he would be without Cirillo for at least a couple of days.

"He was limping around pretty good today and you could tell he was sore," Gardenhire said. "He's available to pinch-hit and that type of thing, but I'd prefer not to use him for a couple of days. Now we'll just see if the shot takes care of it."

The hope is to have Cirillo by the weekend for the team's series against the White Sox, but the Twins have dealt with similar meniscus tears that have lingered. Oufielder Lew Ford had a similar injury in early March that required him to undergo surgery to fix it. Ford was expected to miss four to six weeks and is currently on the 15-day disabled list.

With Cirillo sidelined for at least the rest of this series, Chris Heintz likely could be called into duty as a backup at the corner infield positions. Heintz also has the ability to play second base, although he admitted it should only be in an emergency situation.

An extra day: When the Twins first planned out their rotation schedule for the start of the year, they had figured on keeping Johan Santana on his regular five-day pitching plan.

But that plan has now changed.

After pushing hard on a five-day schedule during spring and then sitting through some long innings in his first start of the year, Santana has decided that he would prefer some extra rest rather than remaining on schedule.

"He wants an extra day," Gardenhire said. "That's what he talked about needing, so that's the way we're going to do."

With Santana deciding to go on six days rather than five, the Twins' rotation will set up like this against the White Sox: Carlos Silva on Friday, Sidney Ponson on Saturday and Santana on Sunday. The Twins will keep the players on their regular five-day schedule following this weekend. The club has another off-day on April 16, but the coaches have yet to decide how they will schedule the rotation at that point.

Emergency plan: Twins closer Joe Nathan could possibly miss Wednesday night's game against the Orioles, but not if his plan works out just right.

Nathan's wife Lisa is expecting their second child, a baby girl named Riley, and is scheduled to be induced for labor on Wednesday morning. If all goes according to schedule, Nathan plans on being back in the bullpen by the middle innings to be available to pitch, if necessary. Nathan has even talked to his wife about leaving for a bit to come to the game if the labor is taking longer than expected, and then returning before the birth.

Gardenhire was informed of Nathan's ambitious plan to be at both the birth and the game, but he wasn't putting any pressure on his closer to be at the Dome.

"I've told all of our guys, our families are first so if you have to be away with your wife after the birth, that's the right thing to do," Gardenhire said. "I'm happy for you and very proud for you.

"But if he's here, even it's his third day in a row for a save, he'll get the ball," Gardenhire said with a smile.

Smell 'em: The Twins' famous phrase for driving in runs last year has taken on a new meaning this season -- smelling teammate Justin Morneau.

The Twins first baseman certainly had quite an odor to him, according to teammates following the team's 7-4 win on Opening Day. That's because he chose to wear the same old Vancouver Canucks Todd Bertuzzi T-shirt that he donned under his uniform all of last season and hadn't washed since then.

Morneau hadn't washed the shirt was because during the offseason, he had contacted current Canucks defenseman Willie Mitchell to get a new T-shirt. Mitchell was hesitant to mess up Morneau's streak, but he sent one anyway. So following Monday's game, when he went 3-for-4 with a home run, Morneau received a text from Mitchell saying, "I hope you had the shirt on. Nice start."

Unfortunately, Morneau had to let his friend down.

"It was a game-time decision," Morneau said of sticking with the Bertuzzi shirt. "Sitting here, I looked up and said, 'I can't change it.' I had to go with it. So I had to tell [Mitchell] he was a late scratch."

Twins tidbits: The Associated Press reported Monday that the Twins' payroll for 2007 will be $71.439 million. That number puts the club 19th overall in team payroll. The Yankees once again are No. 1 with a $195.2 million payroll and the Devil Rays rank last with $24.1 million. ... Laura Osnes, the recent winner of the NBC reality series GREASE, is scheduled to sing the National Anthem prior to Wednesday night's game against the Orioles. Osnes, a Eagan, Minn., native, was awarded the starring role of Sandy on Broadway and the show is set to open later this summer.

Coming up: The Twins host the Orioles for the final contest of their three-game series on Wednesday night in a 7:10 p.m. CT start. Right-hander Ramon Ortiz will get the start for Minnesota as he faces off against Baltimore right-hander Jaret Wright.