MILWAUKEE -- One day after Brewers relief pitcher Tyler Thornburg exited the game in the eighth inning with a tired arm, neither manager Ron Roenicke nor the young hurler seemed too concerned about the issue.

In fact, Roenicke even suggested Thornburg could return to his regular role as a starter before the season is over.

"There's a plan, but that changes at times," Roenicke said. "This is a way of keeping down some of his innings. [Members of the Brewers front office] feel like he has developed as a starter, and we'll see what happens where we get into September, but he could end up starting again at the end of the season and giving us at least a better read on him for next year."

The game in which Thornburg exited on Thursday was his fifth appearance of the season for the Brewers, two of which were starts. It was also the first time he pitched on consecutive days this season, as his 14 Minor League appearances came as a starter.

Thornburg said doctors checked on him as a precautionary measure, and they confirmed he was simply suffering from a tired arm. Roenicke said Thornburg won't be available Friday and probably Saturday, but he expected the 23-year-old right-hander to be ready to go on Sunday.

Pitching out of the bullpen isn't completely new to Thornburg, who was a reliever his sophomore year at Charleston Southern University. But that was in 2009, and of his 47 Minor League appearances since then, 44 were starts.

"When you go that long, your body just doesn't remember how to do that," Thornburg said. "Once your arm gets used to it, and once you do it a couple times, it's completely adjusted."

It will take two or three instances where Thornburg pitches on back-to-back days to get fully acclimated to relieving, he said on Friday. Roenicke said he might just handle the rookie differently, pitching him for a couple innings at a time with more time off in between outings.

"It's always a little bit of an experiment with each individual," Roenicke said. "You know what you want to do with him, but sometimes you have to tweak that a little bit."

Marcum has issues getting loose during BP

MILWAUKEE -- After injured Brewers starter Shaun Marcum's bullpen session on Tuesday brought back positive reviews, his one on Friday wasn't as successful, manager Ron Roenicke said.

"The other day, there were no issues at all," Roenicke said. "Arm strength was good, ball came out good, shoulder [and] elbow both felt fine. Today, he didn't feel as good."

Marcum has been on the disabled list since mid-June with right elbow tightness. He threw 15 pitches on Friday, but pitching coach Rick Kranitz said Marcum's arm "wasn't quite getting loose." Kranitz indicated that Marcum's shoulder was the issue, not his elbow.

Out of action since June 14, Marcum is 5-3 with a 3.39 ERA on the year. Originally, Roenicke expected Marcum to miss a start or two, but the process has taken much longer.

Was Friday's bullpen session a setback?

"Maybe," Roenicke said.

Kranitz anticipated Marcum would play catch on flat ground on Saturday, and then more decisions would be made from there. He has not been told that Marcum would need to be shut down.

"That's how I'm looking at it right now -- no one's hearing alarm bells or anything like that," Kranitz said.

Roenicke said he would likely know more about Marcum's status on Saturday, after head athletic trainer Dan Wright had a chance to look at him. The good news, Kranitz said, was that Marcum's workout was not cut short because of pain.

"So, it's just like, 'Well, do we push through it?'" Kranitz said. "No, there's no need to push through it. ... He's a competitor; he wants to pitch. He wants to get out there as soon as possible. That's all part of it."

Marcum is a free agent after the season.

Wolf will pitch to Lucroy before end of season

MILWAUKEE -- They are not expected to form a battery on Saturday, but left-hander Randy Wolf and catcher Jonathan Lucroy will have to work together before the season is out, Brewers manager Ron Roenicke said.

That duo has had a hard time meshing in the past, for reasons both have declined to enumerate. Wolf instead worked with George Kottaras 71 times over the past three seasons, a pairing severed on Thursday when the Brewers designated Kottaras for assignment and activated Lucroy from the disabled list.

Martin Maldonado will catch Wolf for the third time this season on Saturday against the Nationals, but "Luc is going to catch Randy some," Roenicke said.

"I knew that whether through injuries or changes in personnel, this is something both of them are going to have to get used to," Roenicke said. "It's not like it's one person that isn't comfortable. They both have to get comfortable with each other."

Wolf was very comfortable with Kottaras, who became a good friend off the field. Both of them saw Lucroy's pending return from the DL and Maldonado's solid play and knew that Kottaras could become the odd man out.

"I really don't think there's going to be a side effect when it comes to pitching," Wolf said. "Obviously, I threw to George quite a bit, and you develop a friendship and a bond, like he did with everybody on the team. If you know George, he is a great presence in the dugout and in the clubhouse, and did everything this organization wanted. He went out there with a torn hamstring [after Lucroy broke his hand in May]. He did everything for this team. It's tough to see a guy like that go."

Wolf will make his 20th start of a tough season on Saturday. He is 3-6 with a 5.46 ERA, and has left eight games with the lead and had the bullpen blow the save.

He said he would be "totally fine" with Maldonado, who impressed Wolf during a September callup last year.

"He made sure he caught two of my bullpens and he wanted to know what I do against left-handers, what I do with right-handers, what I like to do with men in scoring position, what my signs are," Wolf said. "He asked questions. I thought that was awesome. It showed me he has the confidence that he deserved to be here, and a desire to get better. What was cool was that, in Spring Training, he had retained all of it."

Asked whether he expected Maldonado to handle most of his starts over the remaining two months, Wolf said, "That's not my job. I talked to Ron [on Thursday] and I told him that, 'I'm not the manager, I don't fill out the lineup card.' He's got to put in the catcher that he wants for that game. I'll handle it both ways."