Lester, who is 34 and has won at least 15 games seven times in his career, gets his second start of the season Tuesday night as the Cubs wrap up a brief two-game series against the Cincinnati Reds at Great American Ball Park.
He's only hoping it's better than his first. The Cubs, off to a 2-3 start after their 1-0 loss Monday in Cincinnati, certainly could use it.
Lester made his seventh career Opening Day start, and his third for the Cubs, but lasted only 3 1/3 innings Thursday even as the Cubs beat the Miami Marlins 8-4. He gave up three runs, seven hits and three walks, and simply didn't look Jon Lester-like with excellent control and a variety of troublesome pitches.
"I wasn't throwing strikes and I wasn't finishing guys," Lester said, "I had no breaking ball. I don't want to dive into it too much. Physically, I felt fine, I just didn't execute."
The Cubs weren't entirely sure what to expect this season from Lester. He was 19-5 with a 3.44 ERA while finishing as the Cy Young Award runner-up as the Cubs won the World Series in 2016 but slipped to 13-8 with a 4.33 ERA last year -- and a 5.17 ERA in his final 15 starts.
In the opener Thursday, his fastball sometimes did not reach 90 mph, which meant there wasn't a great velocity disparity between his fastball and his off-speed pitches.
"Adjustments have got to be made," Lester said.
The Cubs' starting pitching was erratic in their first five games, and manager Joe Maddon said it's already causing stress on the eight-man bullpen.
"This is purely end-of-the-season, September kind of stuff, playoff kind of stuff," Maddon said of running out so many relievers so early in the season.
The Cubs got an effective start Monday from former Rockies left-hander Tyler Chatwood as he allowed only one run in six innings, but he walked six and was outpitched by Reds right-hander Tyler Mahle, who limited Chicago to one hit and struck out seven in 6 1/3 innings.
Three relievers finished, with Raisel Iglesias getting the final four outs for his first save of the season and the Reds' first victory after being swept by the Washington Nationals in a three-game series.
The Cubs were 27-11 against the Reds during the past two seasons, easily their most wins against any opponent in that span.
"He (Mahle) did what we saw him do all spring," said catcher Tucker Barnhart, who went 3-for-4 and threw out a runner stealing. "He was great. I can't say enough good things about him. ... It's a great win. They've given us trouble for a long time."
Lester is 5-1 with a 4.27 ERA in 13 career starts against the Reds, going 2-1 with a 3.66 ERA in six games at Great American Ball Park.
Jose Peraza is a .450 hitter against Lester (9-for-20), and Billy Hamilton bats .368 (7-for-19) with two homers and two RBIs. Eugenio Suaraz is 8-for-27 (.296) with two homers and RBIs, and Joey Votto is 9-for-33 (.273) with one homer and six RBIs.
The Reds will send out left-hander Cody Reed in a spot start to oppose Lester as they wrap up their season-opening, five-game homestand.
Reed, 24, hasn't had much success in the majors yet or against the Cubs. He was 0-7 with a 7.36 ERA in 10 games in 2016 and 1-1 with a 5.09 ERA in 12 games last season. This spring, he gave up 20 hits in 12 1/3 innings.
The left-hander is 0-3 with a 16.20 ERA in 10 innings (18 runs, 18 hits allowed) in three starts against the Cubs.
Cincinnati was expected to use left-hander Amir Garrett as its No. 5 starter, with left-hander Brandon Finnegan still healing from a strained left biceps. But Reed was given the start ahead of him -- though it isn't certain where the rotation will go from here.
"I felt he is more valuable right now in the bullpen," Reds manager Bryan Price said of Garrett.