PITTSBURGH – Ervin Santana's second spring training is getting underway in Fort Myers, Fla.

Santana, who is serving an 80-game suspension after testing positive for the steroid stanozolol, has been throwing in the bullpen and is building toward facing live hitters next week.

"In the next couple of weeks he's going to start pitching in some extended [spring training] games," said Rob Antony, Twins assistant general manager. "In mid-June, he'll start his 16-day rehab [assignment] that he's allowed to have.

"The plan there is to probably run him up to [Class AAA] Rochester to get him three or four starts, then he will be ready to go when the 80 games are up."

Santana has spent most of his suspension in Florida. He has made trips to Fort Myers and stayed a few days to work out and throw off a mound. Antony said Santana is in very good shape.

The first possible game back for Santana, who signed a four-year $55-million contract in the offseason, would be July 4. His suspension was a blow to a team trying to build a deep starting rotation. Twins starters entered Tuesday with a 4.29 ERA that ranked 21st in the majors. Still, it's an improvement from their 5.06 ERA mark last season.

Nunez sticks around

There was speculation that Eduardo Nunez would need a minor league rehabilitation assignment after he recovered from a left oblique strain. But the Twins instead put the infielder on the active roster.

"I was happy," Nunez said. "I didn't want to go to minor leagues to rehab."

Nunez, batting .409 in eight games, worked out at Target Field on Monday to prove he was healthy. Good timing for him, with a pair of interleague road games this week.

"He's a valuable guy," manager Paul Molitor said. "The NL game, versatility of defensive positions, pinch run — if I need to double switch, he's a guy I can use.''

Santana bats first

The Twins offense has chugged ahead with Brian Dozier in the leadoff spot, but Danny Santana was in the role Tuesday at Pittsburgh.

Don't expect the switch to be permanent, though. As Molitor went through his options, he didn't like how the middle of the order looked without being able to use a designated hitter.

"If I left the top [of the order] alone it was [the fifth and sixth spots] where I was struggling to fill those," he said.

So he dropped Torii Hunter to the fifth spot and put Santana to the top with Dozier second.

"The top of the lineup was doing fine," Molitor said. "It was hard for me to tweak that a little, but when I looked at options, I thought it was the right thing to do with Frankie [Francisco Liriano] pitching."

One drawback

Molitor pointed out one problem created by switching to year-round interleague play.

"I think it's more challenging for the American League clubs to find ways to keep your guys ready to do [interleague play] over six months rather than a shortened period," Molitor said. "But the fans like it, and there are some good rivalries."

Etc.

• Outfielder Oswaldo Arcia (right hip flexor strain) is getting close to being sent out on a minor league rehab assignment, Antony said.

• Righthander Casey Fien (shoulder) will throw in the bullpen on Wednesday. If all goes well, he'll head to Class AAA Rochester for a rehab assignment.

• Outfielder Jordan Schafer (sprained right knee) has not yet started rehab.