MINNEAPOLIS -- Twins shortstop Tsuyoshi Nishioka was out of the starting lineup Monday night against the Red Sox after spending the day at the hospital with his wife for the birth of their first child.

Nishioka's wife, Japanese fashion model Naoko Tokuzawa, gave birth to a daughter Monday in Minnesota. Sena Nishioka was born at 8:26 a.m. CT, and weighed 6 pounds, 9 ounces.

"Nishi's at the hospital with his wife right now," Twins manager Ron Gardenhire said two hours before first pitch. "He'll be here later, he'll do his work in the cage, and then he'll come off the bench if I need him."

Nishioka also sat out Saturday's game at Target Field, and has been out of the lineup more often lately as he's struggled at the plate over the last three weeks.

In his last 21 games entering Monday, Nishioka was batting .181 with more strikeouts (15) than hits (13). He did not have a walk or extra-base hit over that period, either.

With Nishioka's wife having a baby Monday, Gardenhire gave him another night off.

"It'll give him the chance to sit back and relax a little bit, he's had a lot going on today," Gardenhire said. "We talked about that. He wants to be here for the game, and that's if everything is OK with his wife and the baby. As we hear right now, it is, but he'll let us know when he gets here."

Baker will see doctors Tuesday about elbow

MINNEAPOLIS -- Twins right-hander Scott Baker has been dealing with lingering discomfort in his throwing elbow, and is scheduled to meet with team doctors on Tuesday to see if he needs to be placed on the 15-day disabled list for a second time this season.

Baker, who allowed five runs on nine hits over six innings in the Twins' 8-6 loss to the Red Sox on Monday, missed 14 games in mid-July after being placed on the disabled list with a right flexor muscle strain on July 7.

He said his elbow "feels average," and that he wants to meet with the club's training staff to see if he can pitch through the discomfort.

"I have no problem pitching with some discomfort as long as it's something that won't get worse," Baker said. "I am OK with it being a little sore. But if you're not effective because of it, it's a different story."

Baker, who had a 3.01 ERA in 17 starts before his injury, has a 4.29 ERA in four outings since being activated from the disabled list on July 23.

"This game is very demanding and you have to be at the top, physically," said Baker, who is 8-6 with a 3.21 ERA on the season. "So it's been tough. It's tough getting the work in in-between [starts]. So we have to talk about it tomorrow and see what they want to do."

Twins manager Ron Gardenhire met with Baker and the training staff after Monday's game, and said the club will do what's best for Baker after meeting again on Tuesday.

"We'll check some things out and see how he feels tomorrow, and then make a decision on what we're going to do," Gardenhire said. "He wasn't feeling great, but he got through it. But it's not a perfect situation, so we're going to talk to everybody and see the best route to go."

Baker said he doesn't want to miss time due to injury, but seemed resigned to going on the disabled list if that's what the doctors think he should do.

"You don't want to be the guy who goes on the DL if that's the decision they make," Baker said. "But you have to do what's best for the team and for yourself, individually."

Morneau progressing well in rehab action

MINNEAPOLIS -- Twins first baseman Justin Morneau turned in an impressive performance in his rehab game with Triple-A Rochester on Sunday, going 3-for-5 with four RBIs and three runs scored, and followed it up with another solid showing on Monday, going 2-for-4 with a double.

Morneau, who underwent surgery to remove a herniated disk fragment in his neck on June 29, is hitting .353 with two doubles in four rehab games with Rochester.

Morneau was originally placed on the disabled list, retroactive to June 10, with a sprained left wrist, before electing to undergo neck surgery later in the month. He was hitting .225 with four homers and 21 RBIs in 55 games before hitting the DL.

Twins manager Ron Gardenhire said Morneau is expected to play in six to eight rehab games before he makes his return.

Gardenhire also added that second baseman Alexi Casilla, who is on the disabled list with a strained right hamstring, will not need to go on a rehab assignment and is still on track to make his return on Friday.

"He'll be activated Friday if everything continues to progress, and he'll leave with us Thursday night," Gardenhire said. "And then we'll activate him on Friday in Cleveland."

Casilla was batting .259 with 15 stolen bases and a team-high 21 doubles in 96 games this season before injuring his hamstring while running the bases against the Rangers in Texas on July 27.

More tests scheduled for Gibson, Slama

MINNEAPOLIS -- Twins Minor Leaguer right-handers Kyle Gibson and Anthony Slama saw team orthopedists, Dr. Dan Buss and Dr. John Steubs, because of right elbow soreness on Monday, and will require further testing on Tuesday.

"Both players will undergo further diagnostic testing tomorrow and we will provide an update during tomorrow night's game," Twins general manager Bill Smith said in a statement.

Gibson was originally placed on the Minor League disabled list with soreness in the flexor muscle area near his elbow and underwent an MRI on Wednesday. The 6-foot-5 right-hander is the 33rd-ranked prospect in baseball and No. 2 in the Twins' system, according to MLB.com.

The 23-year-old could need Tommy John surgery, as Twins Minor League director Jim Rantz said last week the club was worried it could be a torn ulnar collateral ligament.

Gibson, the club's first-round pick in the 2009 First-Year Player Draft, had been struggling recently, as he went 0-5 with a 6.47 ERA in eight starts over June and July. It came after he entered June with a 3.60 ERA and 59 strikeouts in 55 innings.

Slama, meanwhile, was placed on the Minor League disabled list on July 6 because of elbow soreness. The reliever posted a 2.92 ERA with 42 strikeouts in 37 innings with Triple-A Rochester before his injury. The 26-year-old also tossed 2 1/3 scoreless innings with the Twins this year in a brief stint with the club from late May into early June.