The rest of the Cubs had no excuse for sleepwalking through Sunday's 8-1 loss to Minnesota before 35,128 at the Metrodome.
Only a meaningless ninth-inning run off Twins reliever Willie Eyre, Scott's brother, saved the Cubs from being shut out for the second straight time and ninth time this season. They've been swept in three of their last four series, and seven times overall.
The Cubs have lost 10 of their last 12 games, falling to a season-low 18 games under .500.
"We've dug ourselves a deep hole," Lee said. "We can't afford any losing streaks. We need a lot of winning streaks. We need to start playing better consistently."
Lee went 1-for-4 with a single and two strikeouts in his first game since breaking his right wrist on April 19 in Dodger Stadium. He said his timing wasn't there, as evidenced by his misses on winning pitcher Brad Radke's sliders.
Hard as it was to believe, the Cubs actually played worse upon Lee's return.
Among Sunday's lowlights were Matt Murton's bobble of a pickup on Ruben Sierra's single in the Twins' two-run second, Henry Blanco's drop of a throw to the plate from Jacque Jones in the third, Todd Walker and Phil Nevin looking at each other as a chopper off Justin Morneau's bat shot between them for an RBI single in the third, and Murton and Neifi Perez watching a Sierra popup fall between them in the sixth.
"We didn't play very good defense at all," manager Dusty Baker said.
He added it was "physical errors," except for the ball between Nevin and Walker.
"I don't know who wanted the ball," he said. "Somebody's got to get the ball. That was a bad play."
Rookie Sean Marshall (4-6) continued his recent struggles, allowing five runs on six hits and three walks in 42/3 innings.
The Cubs stranded nine runners and went 2-for-11 with runners in scoring position. In Marshall's six losses, the Cubs have scored a total of one run while Marshall has been in the game.
"I've got enough starts under my belt to know how to win and how to keep the team in the game," Marshall said. "Unfortunately, I had a couple of bad pitches that made me pay."