De La Rosa, sidelined since mid-March, did his normal pre-entrance bullpen routine, threw eight warmup pitches off the mound and 26 competitive pitches to hitters.
He will begin a rehabilitation assignment with double-A Arkansas on Friday or Saturday and hopes to be activated April 11, when the Angels return from a six-game trip to Houston and Seattle.
"I felt good, I felt normal," said De La Rosa, a hard-throwing right-hander who went 6-1 with a 2.86 earned run average in a team-high 75 games last season. "There are just some little mechanical things that will come with facing more hitters. I'm close."
Burnett, who suffered a setback in his return from elbow surgery in late March, threw 25-30 pitches in the bullpen and 16 pitches to hitters.
The veteran left-hander, limited by elbow problems to 13 games last season, will continue his rehab at the team’s extended
"Today was a huge step for me, to come out of it feeling good," Burnett said. "I don't know how long it's going to be, but the way I'm throwing the ball, I'm close."