Hart was examined by head team physician William Raasch on Monday and will stay with the team throughout its first homestand of the season. He was sensitive about the notion that he's facing a mental hurdle in addition to a physical one after reading some comments about his progress from earlier Monday.
"He's still trying to push things to get to 100 percent; he's not there yet," manager Ron Roenicke said Monday morning. "He still feels it a little bit on a full swing and he still feels it a little bit when he's trying to throw hard.
"Maybe I shouldn't say he still feels it. He feels that if he does throw it, there's going to be a little tightness there, and he's got to get through that. He's not going 100 percent yet. There is not a timetable."
Hart has to be 100 percent confident both throwing and swinging the bat before the Brewers allow him to begin a Minor League rehabilitation assignment.
With Hart sidelined, the Brewers are playing without a bat that produced 31 home runs and 102 RBIs last season.
There was more encouraging news on two other injury fronts:
Catcher Jonathan Lucroy, coming back from a fractured right pinkie finger, was a full participant in a Minor League game Sunday, Roenicke said. He'll play an exhibition game between Double-A Huntsville and Class A Brevard County on Wednesday in Florida, and then will travel with the Huntsville club for its Thursday season opener.
Zack Greinke's first bullpen session should come before the Braves leave town on Thursday. Once Greinke begins throwing off a mound, head athletic trainer Roger Caplinger will have a much clearer timetable for his return.
"He'd like to move a little faster, but Roger has the clamps on him right now," general manager Doug Melvin said. "If there's a point you want to speed it up, it should be at the end of the process, not at the start of the process. Right now, we have to build up the arm strength."