Jon Lester is never one to mince words about his performance after a tough outing.

Sunday night, he delivered his most brutally honest assessment yet.

“Just giving up too many runs, too many hits, too many baserunners, too many of everything,” Lester said after Sunday’s 7-3 loss.

He lasted 3.1 innings against the Cardinals, giving up 5 runs on 6 hits and 2 walks including a pair of homers.

Lester’s ERA currently sits at 5.80 on the season and over his last 5 starts, he’s given up 24 earned runs on 40 hits in 23.1 innings pitched.

He admitted Sunday night he is not sure where to go from here to find his confidence again.

“You guys have seen the line scores — there’s not much confidence behind that right there,” Lester said. “The work we’re putting in on the side and in between starts obviously isn’t translating into starts. I don’t know what that is. Try to take positives out of every five days, but there’s not many.

“I pride myself on work and pitching innings and keeping my team in the ballgame and that obviously, frankly, is not the story right now. It’s very frustrating. When frustration comes in, obviously there’s not a lot of confidence. Continue to work.”

After Sunday’s loss, the Cubs now have only a 1.5-game lead over the Cardinals in the NL Central with three weeks left to play.

When asked what the team needs to do over the last few weeks of the regular season, Lester once again took accountability for his performance.

“Obviously we need to play good baseball,” Lester said. “I feel like we’ve done that fairly well, but when your starter every five days puts you behind the eight ball, it’s hard to come back from those days. It’s hard for these guys to grind when you’re constantly putting them behind.

“They did a good job of working at-bats tonight. I did a great job of giving up the lead and when you continually do that, it kinda breaks their spirits as well.”

His manager and former personal catcher, David Ross, offered the same assessment.

“I think he’s just fighting himself right now, trying to find his rhythm, trying to find some angle to his pitches, get the cutter back,” Ross said. “He just doesn’t look like himself out there right now. The guy that I’ve known for a long time and I know he’s working hard to get back to that and he’s extremely frustrated. He expects much better from himself, I know that.

“It’s part of baseball for sure, just having some stretches where you’re not throwing good or hitting good or maybe making some errors in the field and right now, it’s just a stretch Jon’s going through and doesn’t look real sharp.”

Lester got out to a great start to the season, carrying a 2-0 record and 1.06 ERA through his first 3 outings.

The Cubs currently have both José Quintana and Tyler Chatwood on the injured list and Alec Mills is also working to regain his early-season form, so they could use a quick turnaround from their veteran southpaw.

If the Cubs keep the same schedule, Lester’s next start will come Friday against the Brewers in Milwaukee.