Bills cornerback E.J. Gaines has been placed on injured reserve due to a groin injury, ESPN’s Field Yates tweets. 
Gaines sustained the injury in practice and was expected to miss a few weeks initially. Following the IR designation, he will now not be eligible to return until after Week 8.
A sixth-round selection by the Rams in 2014, Gaines spent two seasons with the team before being dealt to the Bills in 2017 in the same deal that sent Sammy Watkins the other way. He played one season with the Bills before signing a one-year deal with the Browns for 2018. Following an injury-shortened campaign, the cornerback returned to the Bills for 2019 on a one-year, $3.6MM contract.
Plagued by injuries in recent years, Gaines is coming off his one season with the Browns in which he appeared in six games, including two starts, but was lost for the season after suffering two concussions in a month’s time.
After placing Gaines on IR, the Bills brought in veteran cornerback Captain Munnerlyn, who is familiar with head coach Sean McDermott from their time with the Panthers.