Now Plouffe is starting to reward that faith.
"I have tremendous respect for Gardy for having the confidence in me," said Plouffe, who was hitting .135 with three homers and six RBIs on May 18. "I talked to him today about that. I appreciate the opportunities and hopefully they keep coming."
In his past 14 games, Plouffe is hitting .313 with six homers, four doubles and 11 RBIs, a surge that has coupled with Diamond's emergence as a front-line starter to key a run of victories for the once-hapless Twins.
"Right now, there's a whole different atmosphere in this clubhouse and on the field," Gardenhire said. "That's a start. You have to feel like you can win every day and that starts with our starting pitching."
Diamond (5-1) allowed seven hits and struck out five, and Joe Mauer added three hits and two RBIs in his return from a sprained right thumb to help the Twins (24-34) to their ninth victory in the past 11 games.
Jeff Samardzija (5-4) gave up eight runs and nine hits in 3 2/3 innings, tying his shortest outing of the season for the Cubs, who have lost 20 of their past 24 games.
Alfonso Soriano hit a two-run homer in the eighth for the Cubs, his 12th in the past 24 games.
For the first six weeks of the season, the Twins and Cubs were vying for the title of the worst team in baseball. But after starting the season 15-32, the Twins have shown some signs of life thanks in large part to the surprising emergence of Diamond in their starting rotation.
The former Rule 5 draft choice struggled mightily in the minors last season and was called up this season almost out of desperation to try and help the Twins' rotation. The left-hander has been nothing short of superb, allowing eight earned runs in his seven starts for a 1.61 ERA.
"We've been trying to attack inside the whole time," Diamond said. "I found out last year that was my game plan and my style of pitching. Just trying to build off that and develop the other pitches around it."
He had plenty of breathing room to work with against the flailing Cubs, thanks to an uncharacteristic off day from Samardzija.
Samardzija has had an impressive season for the Cubs, entering the game having allowed three earned runs or fewer in eight straight starts. His fastball was again humming around 97 mph, but the former Notre Dame receiver was pummeled in the fourth.
The Twins had six runs and seven hits in that inning alone, getting four doubles and two hits from Mauer, the last an RBI double off the wall in left field that made it 8-0.
Plouffe hit a solo homer in the fifth and Mauer and Josh Willingham had RBI singles in the sixth to make it 11-0.
Samardzija didn't make it out of the inning, giving up a two-run double to Plouffe, an RBI double to Denard Span and another run on an infield single from Ben Revere before yielding to Casey Coleman. The right-hander also lasted on 3 2/3 innings in a start against Miami on April 19.
Diamond was able to keep Soriano, who hit two towering home runs in a 10-inning loss on Friday night, in the yard, yielding only a single to the slugger in the sixth inning.
By the time Soriano did go deep, a second-decker to left field off Jeff Gray that made it 11-3, the game was already out of reach.
"We still have a long ways to go here. We're 10 games below .500 and we've been playing some pretty good baseball," Gardenhire said. "That tells you how far we dug ourselves a hole."
Span had two hits and an RBI after not starting on Friday night because of an illness. ... Willingham extended his hitting streak to 12 games with a single in the first inning. ... The Twins send LHP Francisco Liriano (1-6, 6.46 ERA) to the mound on Sunday for the series finale against RHP Ryan Dempster (1-3, 2.59). Liriano has pitched well since rejoining the rotation two starts ago, going 1-1 with a 0.75 ERA and 17 strikeouts in 12 innings. Dempster has probably been Chicago's most reliable starter, holding opponents to a .212 batting average. He pitched seven shutout innings in a win over Milwaukee in his last start.