Harvin was the Seahawks' top receiver, and several people wondered if their passing game would take a hit without him.
Reports later emerged that Harvin was part of some locker room confrontations and wasn't popular with every member of the team.
The trade ended up being a blessing in disguise for the Seahawks. They went 9-2 in the regular season after the trade, and are on an eight-game winning streak, including the playoffs.
Seahawks receiver Doug Baldwin emerged as Seattle's top passing targets after the trade, and he admitted the negative press surrounding the trade fueled the team's strong finish to the season:
"I think we just got the negativity and the disrespect in a different way, saying we miss Percy, we miss Golden [Tate] or the no-names that are out here at receiver. We enjoy that. It adds some motivation, it adds some flair to it and we embrace it. I've got a shirt underneath my sweatshirt that says 'Pedestrians With Attitude.' So we enjoy the label because we embrace it."
Seahawks head coach Pete Carroll added that trading Harvin ended up being "better for our team to move on."
Baldwin finished as the Seahawks' leading receiver with 825 yards, but Marshawn Lynch was the biggest beneficiary of the trade. In the first five weeks of the season, Lynch averaged 15.8 carries per game, which jumped to 18.2 in the final 11 weeks. After the trade in October, Lynch's average yards per rush went up from 4.5 in October to 4.7 in November to 5.1 in December.
The Seahawks seemed to find their identity after the trade, and it helped lead them to the Super Bowl.