The Eagles have a proposed trade in place that would send Pro Bowl running back LeSean McCoy to the Buffalo Bills for linebacker Kiko Alonso, according to two NFL sources.

The trade cannot be finalized until Tuesday, when the new league year opens at 4 p.m. The blockbuster move sends the Eagles' all-time leading rusher to Buffalo for the 24-year-old Alonso, who played under Eagles coach Chip Kelly at Oregon.

Kelly spoke at a fund-raiser in Cherry Hill on Tuesday night, but when reporters asked about the McCoy trade, Eagles vice president of team security Dom DiSandro ushered him out the back door.

"I just spoke with the Eagles organization, and there is no trade for LeSean at this time," McCoy's agent, Drew Rosenhaus, wrote on Twitter. "There have been discussions but nothing finalized."

One source close to the situation said the trade - which involved no other compensation for either team - was "a done deal." The move would free up $8.55 million in cap space for the Eagles.

McCoy, who will turn 27 in July, had not talked to Kelly when the news of the trade was first reported, a source close to the running back said. He was in Miami training and learned of the deal from Rosenhaus.

The trade didn't come as a complete surprise. Those close to McCoy believed that he was on the block but that he would be involved in Kelly's attempt to move up in the draft for Oregon quarterback Marcus Mariota. Instead, the running back will end up being part of a swap for another Duck.

Rumblings that the Eagles coach will do whatever it takes to get Mariota persist, and some sources around the league believe a trade with one of the teams with a high draft pick could be on the horizon.

Kelly, who was given complete control over football operations this offseason, has been clearing the roster of high-profile players who either predated his arrival or were acquisitions headed by former general manager Howie Roseman.

Kelly was the driving force behind the release of Pro Bowl wide receiver DeSean Jackson last March. He cut guard Todd Herremans last week and will do the same to linebacker Trent Cole this week. Herremans and Cole, drafted in 2005, were the longest-tenured Eagles.

The Eagles also announced the release Tuesday of cornerback Cary Williams, who was signed during Kelly's first offseason with the team. There could be other veterans to follow, most notably linebacker DeMeco Ryans, who is coming off the second ruptured Achilles tendon of his career and will likely be replaced by Alonso.

The 6-foot-3, 238-pound Alonso missed all of the 2014 season with a torn anterior cruciate ligament in his left knee. He tore the ACL in his right knee in 2010 and missed all of his sophomore season at Oregon. He was already suspended from the team after he was cited for driving under the influence earlier that year.

A year later, he was arrested and charged with felony burglary, criminal mischief, and criminal trespass. Kelly suspended him from the team indefinitely. The burglary charges were eventually dropped, but Alonso pleaded guilty to criminal mischief.

Kelly lifted the suspension before the 2011 season, and Alonso avoided getting into further trouble in his final two seasons. And yet, when Kelly had an opportunity to draft his former player in the second round in 2013, the Eagles selected tight end Zach Ertz with the 35th overall pick.

Alonso had one of the best seasons by a rookie defensive player in 2013. He recorded 159 tackles and four interceptions in the Bills' hybrid defense. New Buffalo coach Rex Ryan had plans to shift Alonso to outside linebacker for this season, according to reports, but Alonso apparently wasn't happy about the move and wanted out.

He will be penciled in as the Eagles' starting inside linebacker alongside Mychal Kendricks.

The Eagles now have a gaping hole at running back. Darren Sproles is a strong backup and complement but is unlikely to carry the load of a starter. Chris Polk is a restricted free agent and should return, but he remains inexperienced.

Kelly could look to free agency to fill the need. The Cowboys' DeMarco Murray is set to hit the market and could be more of stylistic fit (read: a north-to-south runner) than the shifty McCoy was in the Eagles' offensive scheme. The draft is considered deep at running back.

Kelly may believe that he does not need a high-priced tailback. His maneuverings in two years have suggested that he values his system over talent, and Herremans reiterated that sentiment during an interview with WPEN-FM (97.5) on Monday.

McCoy knew that the Eagles were going to have a difficult time bringing him back at his 2015 salary of $10.5 million. He would have cost the Eagles nearly $12 million against the salary cap. The Bills now take on the remaining three years of his contract, although only $1 million is guaranteed, and the Eagles will have more than $50 million in cap space.

McCoy had said that he was open to restructuring his deal, but he also said he wouldn't take a pay cut. The Eagles never approached McCoy about a new contract.

He will leave the team as the franchise's all-time leader in rushing with 6,792 yards. Over the last five seasons, McCoy had rushed for more yards (6,155) than any other running back in the NFL.

Drafted in the second round out of Pittsburgh in 2009, McCoy became a fan favorite almost immediately. His moves dazzled Philadelphia, and, by his second season, he eclipsed 1,000 yards rushing. He was voted to his first of three Pro Bowl appearances in 2011 and set a career high with 1,607 yards on the ground in Kelly's first season.

But McCoy regressed last year and his use in the red zone and the passing game decreased. With the shelf life for NFL running backs short, Kelly decided to part with arguably the Eagles' best player.

No one is safe, and no decision can be ruled out.