"I think they just want to keep me ready, in case someone gets hurt or starts to struggle real bad," Morton said.
Manager Clint Hurdle essentially acknowledged as much a few days ago, when he said Morton is being kept on a throwing schedule "to keep his arm alive."
Burnett was diagnosed with a sports hernia in the middle of April, but he's continued to take his regular turns for the Phillies, deciding to postpone any needed surgery until the offseason.
Morton is clearly sensitive to any reference to the two pitchers' respective statuses, reminding all that "I pitched with it until I was asked to go on the DL. I wanted to keep pitching. I didn't want to go on the DL."
"I talked to [Burnett] quite a bit," Morton admitted. "He's been pitching with it. I was pitching with it. He's a gamer. His situation, I think, is a little different, so he wanted the ball."
Burnett's contract with the Phillies includes a clause that vests his 2015 salary at $12.75 million with his 32nd start; he made No. 31 against the Bucs on Thursday. Morton is in the first year of a three-year, $21 million deal.
Morton began experiencing the effects of the hernia in early June. He remained in the rotation until going on the DL on Aug. 17 -- three days before Gerrit Cole came off that list.
"We had five other guys who were doing more than their fair share, and Cole coming back," Morton said. "It wasn't that I was incapable of pitching ... but the effectiveness. We're in a playoff race. I'll go pitch right now -- give you all I got. It's just that [this] is the smartest thing for the team."
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. This story was not subject to the approval of Major League Baseball or its clubs.