The right-handed starter, who is on the disabled list with a hyperextended left knee, pitched a three-inning simulated game on Sunday afternoon and reported no physical issues.
“I think the most important thing is that the four (types of) pitches (had) the proper definition and shape to them,” manager John Farrell said.
The manager added that there is no time frame yet for Buchholz's return, but the next step will be planning a minor league rehabilitation assignment.
“The next thing will be to get him some reps in a game,” Farrell said.
Buchholz was 2-4 with a 7.02 ERA before going on the DL May 28 (retroactive to May 27).
Farrell added that Buccholz at times has shown some mechanical issues -- which the team has tried to help him correct with video -- that may have contributed to the injury.
Doubront lined up for rehab starts
Left-handed starter Felix Doubront, who is on the disabled list with a left shoulder strain, is scheduled for rehab starts with Triple-A Pawtucket on Tuesday and Sunday.
“We look to progress him an inning in each outing,” Farrell said.
Doubront pitched four innings in a start for the Double-A Portland Sea Dogs on Thursday night in which he threw 43 pitches, 31 for strikes.
Nava flashes 2013 form
Daniel Nava, who has struggled with a .166 average this season, was 3-for-4 in Saturday night's game.
Two of the left-handed batter's hits were to left field and the other was to right center.
Farrell says the key for Nava to get back to his form of last season, when he hit .303 in 134 games, is hitting the ball to the opposite field and up the middle, as he did on Saturday.
“When he stays inside the ball like that, that's his best path through the strike zone,” Farrell said.
Nava was back in the lineup Sunday, playing right field.
Bradley's deeper numbers
While center fielder Jackie Bradley Jr. is batting only .202 this season with a home run and 21 RBIs, he's one of the team's best with runners in scoring position. Bradley is 15-for-50, for a .300 average, in RISP situations. Among Boston regulars who have played the entire season, that mark is second only to catcher A.J. Pierzynski, who is at .333 (16-for-48). Bradley was 1-for-3 with a RBI single in his only RISP chance on Saturday night. ... Third baseman Xander Bogaerts was 2-for-5 with a run scored on Saturday night and has reached base in 23 of his last 25 games. He is batting .353 (36-for-102) in that span.