BOSTON Though CF B.J. Upton was out of Tuesday's lineup against the Red Sox, manager Joe Maddon said it wasn't for disciplinary reasons. Maddon said sitting Upton had nothing to do with his lack of hustle for a ball in left-center in Sunday's loss, a play which led to a much-publicized dugout confrontation with 3B Evan Longoria. On Tuesday, Upton pinch-hit and hustled to leg out a triple in the eighth inning. Maddon said Upton could 'possibly' return to the lineup tonight. Maddon said he sometimes gives players a day off after an off day, and Upton is 3-for-18 against Red Sox RHP John Lackey. 'Just all things considered I wanted to give him tonight off,' Maddon said. Maddon said he had several 'wonderful' and 'frank' conversations with Upton and was pleased with how he responded, with both sides saying they're ready to move on. Upton addressed his teammates before Tuesday's game, though no specifics were given. 'He's a wonderful young man,' Maddon said. 'And that's the thing I don't want to get lost in all this. B.J. is really, really one of my favorite people. This is a good guy, I think sometimes it's interpreted the other way, there's not a malicious bone in his body. 'I think we fixed it, and now it's time to move on.' Upton felt the same way: 'We just cleared the air. We both came to an agreement and we'll just move on.' Maddon has benched Upton on previous occasions when he hasn't hustled, but he said what made this incident different was that 'he's a little bit older, more mature and the conversation can really take a different tone.' Maddon said confrontations like the one Longoria and Upton had 'happen more often than people realize' behind the scenes. And Maddon felt the incident could turn into a positive, much like he felt the dustup between RHP Matt Garza and C Dioner Navarro in Texas did in 2008. 'Sometimes this positive turnaround, something good that's going to happen, is definitely cloaked in some weird clothing at times,' Maddon said. 'Maybe the clothing was this incident and now all of a sudden, we're going to be able to move forward.' BACK IN LEFT: Satisfied with how well his sore left shoulder had progressed, LF Carl Crawford returned to the lineup in his regular spot Tuesday. Crawford tested the shoulder by playing catch and hitting before the game but acknowledged he'll probably have to play with some soreness for a bit. 'I'm going to try to play, do everything I normally do,' Crawford said. 'We rehabbed it a few days, and I think the only way I'm going to be able to test it is to get the live game experience.' Crawford, who went 4-for-5, hadn't been in the lineup since Thursday but was a pinch-runner Friday and Sunday. Maddon said Fenway Park's shorter leftfield helped make it easier to put Crawford back in Tuesday, but he will check with the All-Star on a day-to-day basis whether he can play the field or DH. KAPLER RETURNS: OF Gabe Kapler (right hip flexor strain) was activated from the disabled list, and DH Hank Blalock was designated for assignment. Kapler hit .077 (1-for-13) in four games for Class A Charlotte. MISCELLANY: Maddon said he chose to play Ben Zobrist in centerfield because he had more experience in the outfield this year than Sean Rodriguez (who played right) and had a better familiarity with Red Sox hitters. Red Sox C Victor Martinez went on the 15-day disabled list Tuesday with a minimally displaced fracture in his thumb. 