The Bills acquired offensive tackle Ryan Bates in the deal. Buffalo had a pair of offensive linemen suffer injuries in the Bills' preseason opener against the Indianapolis Colts on Thursday.
Bates signed with the Eagles as an undrafted free agent out of Penn State this off-season. He started 12 games with the Nittany Lions last season before declaring for the 2019 NFL Draft.
The Bills placed tackle LaAdrian Waddle on injured reserve earlier this week after he sustained a torn quadriceps muscle. Bates is valued due to his ability to play both tackle positions.
The San Francisco 49ers selected Harold in the third round of the 2015 NFL Draft out of Virginia. He spent his first three seasons with the 49ers before playing in 13 games with the Detroit Lions in 2018.
Harold signed a one-year contract with the Bills this off-season. Buffalo listed him as the team's fourth-string defensive end on its first unofficial depth chart this preseason.
Harold recorded 10 combined tackles, four sacks and one pass defensed with the Lions last season. He has 95 total tackles, nine sacks, one forced fumble and one pass defensed in his NFL career.