The third baseman is currently batting .241 and hasn't done anything at all since returning from the disabled list in July. The 26-year-old hasn't hit a single home run and is just 8-for-52 on the season.
Now Plouffe might be in danger of losing his grip on a daily spot in the lineup, according to the Minneapolis Star Tribune.
"I'll take some of that responsibility," general manger Terry Ryan said. "Maybe I should have sent him out longer [on a minor league rehab]. He was rusty, but now it's time for him to step up and take that position and give us some thoughts that, 'OK, we don't need to address that.'
"He's at the prime of his career. He's been looking for a spot to call his own, and now here's his opportunity, so I hope he takes advantage of the situation and solidifies that. He's got the rest of the year to do it."
Plouffe still has time to turn it around, but the leash certainly sounds as though it's getting shorter.