And surprise, surprise, Gailey hasn't entirely shut the door on bringing back receiver Stevie Johnson - so long as he keeps in check his colorful and oft-questionable touchdown celebrations.
Wasting little time, Gailey spent Monday charting an offseason course mixed with both change and continuity in a bid to turn around the Bills (6-10) after their seventh straight losing season. It was a year in which Buffalo got off to a surprising start before closing with a familiar thud by losing eight of its last nine, including a 49-21 loss at New England on Sunday.
The first and most significant move had George Edwards being fired as defensive coordinator and replaced by Wannstedt. It's a promotion for Wannstedt after he spent this past year serving as assistant head coach/inside linebackers.
"We're in a production business. That's the bottom line. And we need to get better production," Gailey said. "It just got the point where we needed the change and so we made the change."
The decision didn't come as a surprise after the defense struggled in its second season under Edwards.
Though a rash of injuries played a role, the Bills were over-run giving up a franchise-worst 5,938 yards. Buffalo also allowed 434 points, the second most in team history.
Wannstedt is a two-time NFL head coach - in Chicago 1993-98 and Miami 2000-04 - and has an extensive defensive background. He joined the Bills a year ago after spending the previous six seasons as head coach at the University of Pittsburgh.
There's plenty on the Bills' to-do list after they missed the playoffs for a 12th straight season, the NFL's longest active drought.
Buffalo's offense has it's question marks, too, the biggest involving Johnson, the Bills leading receiver the past two seasons.
In completing the final year of his contract and unsure whether he'll land a new deal with the Bills, Johnson further clouded his future after an excessive celebration penalty led Gailey to benching him for the final three quarters Sunday.
Gailey had warned players of drawing such penalties and said he had no choice but to sit Johnson after the receiver was penalized 15 yards for pulling up his jersey to expose the words "Happy New Year" on his undershirt. It marked the second time this season - and third time in two years - Johnson's been flagged for a TD celebration.
Despite acknowledging he's grown frustrated by Johnson's actions, Gailey said he'd be open to have the player return under the condition the player stops incurring needless penalties.
"To say it doesn't have an impact would be a lie. But you have to look at the whole body of work and not give a knee-jerk reaction," Gailey said of weighing Johnson's value. "I mean, you love what Stevie does on the field before he scores touchdowns, you know? So you just have to decide if he can and we can get that under control."
Even if Gailey's OK with Johnson returning, there's still a question of whether the two sides can work out a contract after negotiations broke down in late November.
Johnson finished with a team-leading 76 catches for 1,004 yards and seven touchdowns, and became the first Bills player to go over 1,000 yards in consecutive seasons.
Fitzpatrick made clear where he stands on Johnson.
"I want my best receiver back," Fitzpatrick said. "I'm a better player with Stevie on my team. And I think he's a better player with me as his quarterback."
Fitzpatrick could use all the help he can get after completing his first season as a full-time starter, and after he signed a six-year, $59 million contract extension in October. Fitzpatrick's production mirrored that of the Bills.
After throwing 14 touchdowns and seven interceptions in his first seven games, Fitzpatrick had 10 touchdowns versus 16 interceptions in his final nine.
That led to a dubious distinction in which Fitzpatrick's 3,832 yards rank third on the Bills list, and his 23 interceptions are the most since Joe Ferguson threw 25 in 1983.
"I think disappointment is probably the best word to describe it," Fitzpatrick said. "It was a very up-and-down 16 games obviously for me, but I think I learned a lot."
Fitzpatrick already has the support of team owner Ralph Wilson who, two weeks ago told The Associated Press, that the quarterback needed better players around him.
Gailey also continued to voice his support of Fitzpatrick on Monday.
"I have a great deal of confidence in Ryan," Gailey said.
General manager Buddy Nix intends to spend the week meeting with players, coaches and team owner Ralph Wilson, and would rather wait a week before providing a detailed assessment on what went wrong this season, and how he intends to fix it.
When it came to sharing a general thought, Nix was surprised by the team's collapse.
"I knew we weren't quite as far along as everybody thought we were," Nix said. "There's no excuse for losing seven games in a row. That was a complete downer and a complete surprise."