Kenley Jansen returned to the Los Angeles Dodgers on Monday and seemed confident that he'll pitch again this season.

The reliever will throw a bullpen session this week, but also says he was told there's a good chance he will need another heart surgery in the offseason. He had his first surgery in 2012 and was prescribed blood thinners in 2011.

He was hospitalized in Denver on Thursday after experiencing an irregular heartbeat and then sent back to L.A. for tests.

ESPN reported that Jansen would miss about four weeks.

"I'm confident that it's not going to be four weeks, and it's not going to be six weeks," he said. "[Aug. 20] is going to be the key to listen to what is going to happen. Right now I'm going to keep taking my blood thinners and hopefully there are no side effects from the medication I'm taking, and I am pretty confident I will be back sooner than later."