What happened to Kenley Jansen? Red Sox pitcher withdraws from Rockies series due to heart condition

Boston Red Sox veteran reliever Kenley Jansen won't be participating in the team's three-game series against the Colorado Rockies starting on Monday. Red Sox manager Alex Cora confirmed the four-time All-Star's absence after Jansen's appearance on the mound on Sunday.

Jansen conceded his first home run of the season on Saturday. Kiké Hernández tied the game in the ninth inning as the Dodgers came from behind to win the game 7-6 in extra innings.

He was called to the mound in the eighth inning on Sunday and ended up conceding three runs as the Dodgers swept the Red Sox. Following the loss, Cora confirmed the reason he called on the veteran reliever with the team trailing in the eighth.

Kenley Jansen won't be traveling to Colorado due to a pre-existing heart condition. The two-time NL Reliever of the Year revealed his previous struggles on trips to Colorado being the reason behind his omission.

“Too many times stuff happened over there with me,” Jansen said. “It started off when I went back to Atlanta. I started having issues, and then a couple of weeks later, I went back to AFib. Just trying to avoid that right now.

The 36-year-old suffers from atrial fibrillation, a condition with irregular heartbeat. Jansen has had trouble pitching at Coors Field as it sits 5,200 feet above sea level. He revealed that his heart needed to be shocked after his three previous visits to the ballpark.

Kenley Jansen's absence a precautionary step by the Red Sox pitcher

Kenley Jansen was unlikely to pitch for a second consecutive game on Sunday, but the veteran reliever asked Alex Cora to be put on the mound as the team would be depleted for the next series starting on Monday.

The All-Star closer doesn't want to risk his condition for the three-game series, especially with the Red Sox eyeing a post-season berth where his services will be of utmost importance.

“We’re trying to get to the postseason. I don’t think that’s a great time to go there and mess things up. The next thing you know, it’s going to hurt the team more,” Jansen said.

The Red Sox will be a player short for the series but Jansen is expected to be back in action when they take on rivals New York Yankees at Fenway Park in a three-game series starting on Friday.