The umpire started to walk toward the mound, but catcher David Ross stepped between Lester and Fletcher. Cubs manager Joe Maddon then came out and had a heated discussion with Fletcher, and somehow no one was ejected.
"I didn't say anything directly to him," Lester said. "I don't know why he was so upset. I had my head down when I was yelling. Nothing was directed at him ... and I don't know what was going on. It had nothing to do with the umpire's strike zone. I have to execute better."
Lester ended up frustrated and with another loss, dropping to 4-6 in his first season with the Cubs. Lester gave up four runs on four hits and four walks over four innings, his shortest outing since July 22, 2012, when he also lasted four innings.
"The fastball was not going where he wanted it to go, and that was a problem," Maddon said.
Ross said he talks so much to umpires, they probably get tired of him by the end of the game. He's been involved in heated discussions, but those are usually done less publicly. Thursday was a little different.
"I've never had to go step in front of an umpire that I know of," Ross said. "I don't think it's that big a deal."
Ross said there may have been some bad feelings from Lester's May 11 start against the Mets, when Fletcher was behind the plate. The Cubs lefty got a win that day, but he also walked four over six innings.
"Andy wanted to make sure [Lester's reaction] wasn't directed toward him," Ross said. "I was making sure [Fletcher] would talk to me and not Jon."
Lester has definitely struggled this month. In five starts, he's given up 17 earned runs over 26 2/3 innings for a 5.74 ERA.
"It just gets back down to executing pitches and maybe not trying so hard to make the perfect pitch," Lester said. "It's easier said than done."
Lester is also a little frustrated at the National League. Maddon lifted the lefty for a pinch-hitter in the fourth when the Cubs had two on and two outs. If Lester had given up four runs early in an American League start, he might have stayed in the game longer than he did Thursday.
"It's different," Lester said. "I felt like I got better, things got cleaner, location got better, outs got quicker. As a competitor, you want to continue to go out there. Because of the style of play here, you're not allowed to do that. It's something that's frustrating, but at the same time, there's nothing I can do to change it."
Lester did retire the side in order in the third and fourth innings against the Dodgers.
"The one thing I know about Jon Lester is when he gets out on the mound, he gives it his all," Ross said. "That's all I care about."