Starting Friday, the Angels play consecutive series at National League ballparks.
Morales hasn't played first base since May 29, 2010, the day he fractured his left ankle while leaping onto home plate, an injury that cost him nearly two full seasons.
"I still have to wait for the games to start because practices are different," Morales said. "In games, that's when I'll know if I'm ready or not."
Pujols has played 104 games at third base in his career, including seven games last year and one inning in San Diego last month when the teams went into extra innings. He has a .953 lifetime fielding percentage at third base.
Angels manager Mike Scioscia approached him a few weeks ago to find out how comfortable he was playing there.
Pujols said he always travels with a third base glove in case he's called upon.
"It doesn't make any difference, man. You know, I was a shortstop. My dad and everybody's always saying, 'If you can play shortstop, you can play any position,' " Pujols said. "I don't have a problem playing that. He asked me and I said, 'Wherever you put me -- the outfield, third base -- I know how to handle myself.'"
The Angels have the best record in the majors in interleague play since 2007, going 63-30. They have won nine of their last 10 series against National League teams.
Pujols' signing in December pushed both Morales and slugger Mark Trumbo off first base, their natural position. Trumbo has played first base, third base, designated hitter, left field and right field this season, while Morales will be making his debut in the field.
"I don't think it's something we really want to overplay right now, but you don't want Kendrys sitting for six days," Scioscia said. "We'll certainly get him two starts out of six and then see where it goes."