New York Yankees shortstop Anthony Volpe had a cortisone shot in his left shoulder on Wednesday after playing through a small tear in his labrum for more than four months.
Volpe, who also received a cortisone shot after the All-Star break, aggravated the injury during Sunday's game and will again sit out Thursday -- his third absence in a week.
Boone said Volpe remains in "day-to-day mode" and may also miss the opener of a three-game series at Boston on Friday.
The Yankees don't expect Volpe to be placed on the injured list. Boone said the shortstop will probably have an MRI after the season.
The small tear was first discovered in early May after he felt a pop in his shoulder.
"He's aggravated it, maybe a couple of times, Sunday being one of them and each time it's kind of added to -- I think it's just a swelling issue," Boone said.
"... [The MRI] shows a little bit more of a labrum tear but nothing that we think is going to land him on the IL or nothing that he can't continue to play through. He already feels better [Thursday]. I don't expect it to be an issue but that being said, if he goes out there and aggravates it again, we may have to look at it more."
Volpe has 19 home runs and 70 RBIs this season, but he's batting just .206 with a .268 on-base percentage and 140 strikeouts in 141 games. His 81 wRC+ (weighted runs created plus) -- which attempts to measure a player's offensive production with adjustments for ballpark effects, league run-scoring environment, etc. -- ranks 141st out of 146 qualified hitters this season.
Since June 25, Volpe is batting .171 with a .573 OPS in 63 games.
"I don't think it's been a major factor in his performance or his ability to swing the bat or in his ability to kind of go to the post every day," Boone said.
Jose Caballero has been filling in at shortstop during Volpe's absences.
ESPN's Jorge Castillo and The Associated Press contributed to this report.