Ellsbury wouldn't allow Valentine to tell the media what his latest injury is, but one report said it was a lat strain.
Regardless, Ellsbury clearly didn't want to be shut down for the remainder of the season, even though the Red Sox aren't in a playoff race.
"They said tomorrow -- he should be in there tomorrow," Valentine said. "He's going to do everything today in practice. He's going to actually test everything, they said, today. Then if all goes well, tomorrow will be the day. I hope all goes well throwing and hitting."
Before the injury, Ellsbury had finally rounded back into form. He was 7-for-15 over his last four games.