Cubs ace Jon Lester has likely hit his lowest point in his 14-year career.

The veteran left-hander gave up 11 runs (10 earned) Tuesday in an 11-4 loss to the A’s, the second most in any start of his career.

“What happened is I gave up 11 runs, so it doesn’t matter how I feel,” Lester told reporters following the loss. “Doesn’t matter about a game plan, doesn’t matter about executing pitches, doesn’t matter about anything. I gave up 11 runs, so it really doesn’t matter.”

With eight pitchers out for the Cubs due to injury, the five-time All-Star was asked about the bullpen situation and immediately pivoted the blame, referring to himself as the team’s “weakest link.”

Lester faced 12 batters in an eight-run, second-inning massacre before the A’s dumped on another three in the fourth on a Stephen Piscotty home run. In his past four starts, Lester has given up 35 hits and his ERA has ballooned to 4.46.

“Jon’s been there before,” Cubs manager Joe Maddon said. “This is a waste can kind of a night. You just dump it and move on.”

Although Tuesday’s outing ended the Cubs’ four-game winning streak, recent minor-league call up Duane Underwood struck out all six batters he faced in his season debut.

“That was impressive,” Lester said. “He probably should have started the game.”