Trey Burton was in Clearwater, Fla., Tuesday, throwing out a ceremonial first pitch before the Phillies' game against the Rays. By the time Burton took the mound, he was already an ex-Eagle, at least in theory; though NFL free-agent contracts can't be signed until Wednesday, the NFL Network reported Tuesday that Burton had agreed to a four-year, $32 million contract with Chicago.

Burton, Eagles backup tight end and author of the "Philly Special" Super Bowl touchdown pass to Nick Foles, presumably will become a top target of Bears second-year quarterback Matt Trubisky, under new coach Matt Nagy, an Andy Reid protege who began his coaching career with the Eagles.

Though Burton has spoken of wanting to stay with the Birds during his many appearances since the Super Bowl, the assumption has always been that he would leave in free agency, given that the Eagles have cap issues and are paying Zach Ertz $42.5 million over five years to be their starting tight end. They signaled a big shakeup at that position Tuesday when they released the longest-tenured Eagle, Brent Celek, clearing $4 million in salary cap space.

Burton, 26, came to the Eagles in 2014 as an undrafted free agent from Florida, a player who had bounced around several positions for the Gators (arriving as a QB). It wasn't clear where he would fit in the NFL, but he established himself as a key special teams performer and a strong pass-catcher, in limited action.

When Ertz missed the Dec. 10 game at the Rams last season, Burton caught a season-high five passes for 71 yards and two touchdowns. He finished the season with 23 catches for 248 yards and five TDs, playing just 27 percent of the Eagles' offensive snaps.

Burton was a strong locker room presence and is a close friend of Eagles quarterback Carson Wentz. A year ago, it would have been fair to say wideout Jordan Matthews and Burton were the pass-catchers closest to the franchise QB. Now both are gone, Matthews traded to Buffalo in August. He is a pending free agent.

The "Philly Special" TD was typical of the way Burton could makle an impact while not necessarily piling up receptions. During his Eagles career, he scored on the return of a blocked punt, blocked a punt, recovered an onside kick, and,while lined up at fullback, threw a key block for a LeGarrette Blount touchdown in the NFC Championship victory over Minnesota.