Manager Ron Roenicke wants to work Thornburg into the rotation, possibly implementing a six-man staff, but he said finding a spot to work Thornburg into could be difficult over the next week and a half.
The Brewers have off-days on Sept. 13 and 17, which could make it tricky to add an extra pitcher to the rotation before the second off-day. If that's the case, and Milwaukee can't find a start for Thornburg before then, the righty will likely see some work out of the bullpen.
"If we have him in the bullpen, it's just because we need to have him in a game so he's not too far removed from being in an actual competition," Roenicke said.
Thornburg started for Triple-A Nashville on Sunday, working 3 2/3 innings, and he threw a bullpen session on Tuesday at Marlins Park.
"We're going to go a little bit with him and probably not have him out of the bullpen," Roenicke said. "But if it goes beyond eight days or some time, just to give it a number, then we need to have him maybe actually be in our bullpen to figure it out."