It took the better part of a week before Buffalo's two trades prior to free agency could become official. The moves to acquire RB LeSean McCoy and QB Matt Cassel however, were completed in short order.

The Bills are quickly developing a reputation of being willing to deal under GM Doug Whaley. It may be why the Philadelphia Eagles initiated contact when it came to the trade that landed them one of the best running backs in football.

In an interview with buffalobills.com, Whaley explained how talks of a possible trade for McCoy came together rather quickly with the Eagles, not long after Philadelphia made initial contact with them in late February.

"They reached out after the combine and got the ball rolling there," Whaley said of the Eagles. "It wasn't a lengthy trade process. We reached an agreement pretty much in one day. They asked about some situations to see if we'd have an interest. We gave them a counterproposal and it was to their liking and then we just got approval from both ownership groups and worked out the paperwork and said when the league year begins we'll make it official."

The agreement that dealt one player for another straight up also facilitated in the processing of the trade, but Whaley has shown over the last year that if the trade makes sense he'll pull the trigger. So the opportunity to acquire one of the best running backs in football for an offense that was in need of upgrades was an easy decision.

"In this day and age of football there are very few number one running backs that can carry the load and we feel that he is one of the top three running backs in the league and he can be a number one that's a workhorse so it was very important," Whaley said. "If we were going to trade away an important piece of our defense we were going to get an important piece for our offense in return."

Buffalo got that in McCoy. No other running back over the last two seasons has as many carries of 10 yards or more than McCoy (81). He also ranks in the top five in the league in rushing touchdowns since 2011 with 33.

"If you look at Greg Roman's past it's a run-heavy offense and for us we've got a chance to add a dynamic playmaker to our offense and a guy that scores touchdowns," Whaley said. "Until they change the rules about the team that scores the most touchdowns wins, we're going to keep trying to add guys that score touchdowns."

Buffalo's other trade landed them a veteran quarterback in Matt Cassel, which also materialized in relatively short order. Cassel's production over several years is what set him apart in the eyes of the Bills from what the free agent quarterback market had to offer.

"If you look at his resume he's been a backup, but he's also been a starter and he's won in this league and he's performed well," Whaley said. "So in talking with the offensive staff and Rex Ryan we thought this guy could come in and compete for a starting role. And if he doesn't get it he's that veteran, calming presence behind EJ or whoever else wins the job. But if he does win the job he's proven that he's a winner."

Whaley is referring to Cassel's Pro Bowl season of 2010 when he led the Kansas City Chiefs to a 10-6 record, an AFC West title and the playoffs. And Buffalo's GM wouldn't be surprised if his offensive coaches go back to that Kansas City game tape to see how they might be able to recapture the kind of production where Cassel stood second in the league in touchdown to interception differential with 27 TDs and just 7 INTs.

"I think that's an important key reason why we got a guy like Cassel," Whaley said. "Some of those things we're going to integrate into our offense, not only with Cassel, but with EJ (Manuel) and all the other quarterbacks that we might have on the roster."

Cassel found out about the deal while at his Manhattan Beach home in California.

"I got a phone call from my agent and he said, 'I've got great news. You've been traded to the Buffalo Bills,'" Cassel told Buffalobills.com. "And I wasn't sure I heard him right so I asked him what he said and he repeated it, so as I heard it clearly the second time a smile came across my face and I was excited."

The reason the 10-year veteran had so much enthusiasm for the move was because he was preparing himself to be the backup in Minnesota in 2015. Teddy Bridgewater has been tabbed the Vikings starting quarterback heading into the 2015 season after he stepped in for an injured Matt Cassel in Week 3 last season. Cassel was still under contract with Minnesota. Buffalo's trade to acquire proved to be a blessing.

"It was just the realization that I was going to have the opportunity to compete again for a job," he said.