Burnett, limited to 13 games last season and completing the final steps of a lengthy rehabilitation from August elbow surgery, is "throwing the ball as well as he has in a couple of years," manager Mike Scioscia said on Monday.
Burnett gave up three runs in his debut with the Arkansas Travelers, and has since reeled off four consecutive scoreless outings. The 31-year-old struck out the side on Thursday, then notched back-to-back 1-2-3 innings on Saturday and Monday.
General manager Jerry Dipoto recently saw Burnett pitch and reported that he has great action on his curveball and sinker and is bouncing back well.
"I think Sean is at a stage now where his stuff is where you'd like to see it," Scioscia said. "You just want to make sure that it's there and it's going to stick."
Alden Gonzalez is a reporter for MLB.com. Read his blog, Gonzo and "The Show", and follow him on Twitter @Alden_Gonzalez. This story was not subject to the approval of Major League Baseball or its clubs.