"If you've got guys who've played hard all year long and you've got a chance to win, you need to do something if you can," he said.
In that way, new third baseman Hanley Ramirez changed plenty the moment he walked in the door. Suddenly, a team that had been playing shorthanded for almost the entire season had a dramatically different look.
In just his third game for the Dodgers, Ramirez's two-run home run in the 10th inning Friday night delivered a 5-3 victory over the Giants in front of a rowdy sellout crowd at AT&T Park.
Even if Colletti doesn't do another thing, he has constructed a middle-of-the-lineup combination as good as almost any. This entire season has been a struggle, with both Matt Kemp and Andre Ethier spending time on the disabled list.
Now they're back, and with Ramirez arriving in a trade with the Marlins this week, the Dodgers appear positioned for the long haul.
"He just lengthens our lineup," second baseman Mark Ellis said. "We know exactly what the middle of our lineup is going to look like [with Kemp, Ethier and Ramirez], and that's huge. It's a sense of security."
Indeed, Dodgers manager Don Mattingly said there's a lineup chemistry good teams have, with one player feeding off another, with each making others better by having tough at-bats.
"It's not one guy," he said. "It makes everybody a little bit better. It makes that guy work a little bit harder."
Colletti said the mere fact that he was able to go out and add an impact player -- and left-handed reliever Randy Choate -- was an emotional boost.
"They knew we'd been paying attention and appreciated what they'd done," Colletti said. "And if we can do more, we'll do more."
As for Ramirez, he seemed to be having the time of his life Friday night as he circled the bases smiling and bringing his hands to his eyes, making circles resembling eyeglasses to look back into the visitor's dugout. That gesture was prompted by shortstop Dee Gordon, who has emphasized his new team is about nothing except playing hard and having fun.
"I've been told to go out there and have fun," Ramirez said. "That's the key."
After seven seasons with the Marlins, including the last five as the face of the franchise, Ramirez said there are times he still can't believe he's wearing a different uniform.
"I'm so happy to be part of this organization," he said. "It's a lot of history. I'm very proud to be here and play for the L.A. Dodgers. It's good. It gives me a lot of energy. I'm going to give 100 percent."
Ramirez left the Marlins at a time when his numbers are down dramatically. Injuries and a position switch from short to third last offseason may have contributed to the declining production.
And after he was traded, there was a series of anonymous quotes critical of his personality and production.
"You never know what someone has been through," Colletti said. "We know what kind of player he is. Now has he had a couple of years where it wasn't what it was? You're talking about someone who was on a historic pace a couple of years ago. The day we got him we were better for having him. If we can make ourselves better, it's worth it. Even if it's just a tiny bit better."
The Dodgers haven't been to the World Series in 24 years, and with new ownership, Ramirez is a symbol to both fans and players that a new era has begun. And the Dodgers say they intend to do whatever they can to make his transition painless.
"It's up to us to make him feel welcome and be part of the team," Ellis said. "He doesn't have to come in and be anything other than himself. It's up to us to include him and make him feel comfortable. He's a breath of fresh air, a new energy."
Richard Justice is a columnist for MLB.com. Read his blog, Justice4U. This story was not subject to the approval of Major League Baseball or its clubs.