Morrison was an option to play first base had Miami traded for an outfielder. The 24-year-old just wants to be in the lineup, no matter the position.
"I don't care where I'm at," Morrison said. "I'll play where they want me to. I'll catch, but we won't win many games.
"I just want to play and help my team win games. If that's at first base or left field, that doesn't matter to me."
A natural first baseman, Morrison made the switch to left field in 2010 when he was called up from Triple-A.
Gaby Sanchez had been entrenched at first base since '10, but the addition of Lee prompted Sanchez to be optioned to Triple-A New Orleans.
Manager Ozzie Guillen is monitoring Morrison, because he's been playing with a sore left knee all season.
In December, he had surgery on his right knee, and it's acted up on him since the third inning on Tuesday. Guillen was close to taking Morrison out of that game, but didn't make the switch.
On Wednesday, Morrison didn't start, but he delivered a game-tying three-run homer as a pinch-hitter in the seventh.
Morrison was in the starting lineup on Thursday.
"It's just not 100 percent," he said. "I wasn't comfortable. But I put some [Icy Hot] on it and it kind of loosened up."
Morrison stayed in the game on Tuesday because the team needed him.
"I know [Guillen] was wanting me to come out, but I didn't want to," Morrison said. "I was like, 'I want to stay in.' Kind of the way we've been playing, I wanted to make a statement as far as it's not over, and you've got to keep grinding. I don't care where I'm at."