PITTSFORD, N.Y. — Jordan Matthews' first chance to fill Sammy Watkins' starting job with the Buffalo Bills ended with the newly acquired receiver sustaining a chest injury.
Matthews finished the two-hour practice on Sunday before being escorted off the field by a trainer. The Bills were unable to provide an update on the nature or severity of the injury because Matthews was still being evaluated.
It's unclear when Matthews might have been hurt, though he did fall hard along the sideline while attempting to make a leaping catch in one-on-one coverage with cornerback Shareece Wright during a team drill.
It was not the type of debut the Bills were counting upon in returning to training camp since completing two blockbuster trades on Friday.
Buffalo gave up starting cornerback Ronald Darby to acquire Matthews and a third-round draft pick from Philadelphia. The deal coincided with Buffalo trading Watkins to the Los Angeles Rams for cornerback E.J. Gaines and a second-round pick.
As important as acquiring the two picks were for a team looking ahead to rebuilding through the draft, Matthews was a key addition in addressing Buffalo's more immediate needs.
Though not considered as dynamic of a deep threat as Watkins, Matthews has been consistent in his first three seasons with the Eagles. He was Philadelphia's most productive receiver with 2,673 yards and 19 touchdowns, and became just the fifth NFL player to top 65 catches and 800 yards in each of his first three seasons.
Matthews saw playing time with both the first- and second-string offences among what's now become an entirely retooled group of receivers, including Anquan Boldin who signed last week.
Before practice, coach Sean McDermott was already projecting seeing both Matthews and Gaines play in a preseason game at Philadelphia on Thursday.
Gaines was surprised in learning of the trade, and welcomed the chance to prove himself after the Rams deemed him expendable.
"Just being somewhere that I feel wanted," Gaines said following practice. "Being somewhere that I feel like expects me to come in and make plays and knows what I can do on the football field, I'm just excited."
A sixth-round pick out of Missouri, Gaines won the starting job as a rookie in 2014, before missing the next season with a foot injury. He started 10 games last season before his job security was placed in question after the Rams acquired Kayvon Webster in the off-season.
In Buffalo, he'll compete with Wright, first-round draft pick Tre'Davious White and Kevon Seymour for the two starting jobs on what will be a completely revamped secondary following Darby's departure. Buffalo also features two new starting safeties in free-agent additions Micah Hyde and Jordan Poyer.
In other developments, McDermott continued expressing concern with starting left tackle Cordy Glenn missing practice due to a sore left foot that has bothered him the entire off-season.
Without going into detail, McDermott would only say, "we're hopeful," when asked if Glenn will be ready for the start of the season. He also acknowledged the team will have to develop a contingency plan in the event Glenn isn't ready.
Backup Seantrel Henderson won't be available because he will miss the first five games to complete serving a 10-game suspension issued last year for violating the NFL's substance abuse policy. That leaves third-year player Michael Ola and rookie third-round draft pick Dion Dawkins competing for the primary backup spot.
Glenn was held out of Buffalo's preseason-opening 17-10 loss to Minnesota and did not practice the following day. He also missed two practices 10 days ago after travelling to Charlotte, North Carolina, to have his foot examined by a specialist.
NOTES: Safety Colt Anderson was cleared for practice and activated from the physically unable to perform list because of a foot injury. ... Rookie QB Nathan Peterman was rewarded for his preseason game performance by practicing with the second-string offence ahead of veteran backup T.J. Yates. Though crediting Peterman for going 13 of 25 for 112 yards and a TD against the Vikings, McDermott said he's still evaluating as to whether to change the depth chart.
AP NFL website: www.pro32.ap.org and www.twitter.com/AP_NFL