"There's no excuse for it. It can't happen, especially in the middle of a pennant race," the 23-year-old center fielder said a day after his gaffe.
Benched three times in the past two weeks for not hustling, Upton looked shocked Monday night when he was thrown out at second base on what should have been a routine double.
Upton went into a trot coming out of the batter's box on a drive that hit the left-field wall instead of clearing it. When he loped into second, Angels first baseman Mark Teixeira alertly trailed the play, caught a one-hop throw and slapped a tag on Upton.
Upton left Tropicana Field without speaking to reporters after the 6-4 win in a matchup of division leaders.
"It wasn't something that I think I was ready to deal with last night," Upton said. "I've got to do what I can to push it behind me and move on. The last thing I want to become is a distraction to this team. We've got something way too good going on right now to have to deal with this."
The Rays lead Boston by 4½ games in the AL East.
Upton was benched for one game on Aug. 6, the day after he failed to run hard on a grounder back to the mound against Cleveland. Manager Joe Maddon removed him in the middle of an inning at Texas for not hustling on a double-play grounder last Friday, then left him out of the lineup for Saturday's game against the Rangers.
Floyd vowed, "He's going to get it right, trust me."
"We just want to win ballgames," Upton said. "I can't let that happen for my sake, and for the team's sake, so we can move on and get where we need to be."
Pena called Upton " a great kid" who is receptive to input from teammates.
"We feel comfortable talking to each other about anything," Pena said.
"I don't think people should be quick to judge B.J. So what there have been other incidents that obviously shouldn't have happened? He knows it. I know it. Like I said [Monday], no one cares worse than him when something like that happens."
Maddon is satisfied with the way the latest play was handled.
"It's all going to work out. ... I really want to move beyond all this. The focus needs to be on how well we're playing," the manager said.
"We're going to take care of it, but again, it happens. I think we've addressed it in a forthright manner, and because of that, things will go well."