National Football League roundup

The 31-year-old Pitta, who underwent hip surgery in 2013 and 2014 before coming back last season to lead all team tight ends with 86 receptions, is undergoing tests to determine the severity of the injury, the team announced.

Friday's OTAs were not open to reporters, but the team said Pitta stretched for a catch, fell to the turf and then could not put weight on his leg as he tried to get up.

ESPN and NFL Media both reported that the team fears the injury could be career-ending.

--

Rookie running back Joe Mixon signed a four-year contract with the Cincinnati Bengals, the team announced.

Mixon will receive approximately $5.5 million over the deal, according to NFL Network.

Mixon was a second-round choice (48th overall) in the recent draft but was considered a first-round talent. His stock dropped due to an incident in which he punched fellow Oklahoma student Amelia Molitor in the face and broke her jaw in multiple places. Video of the 2014 incident was released in December 2016.

--

Retired quarterback Michael Vick hopes to return to the NFL as an assistant coach.

The four-time Pro Bowl player told ESPN's Adam Schefter he wants to pursue the second career in the NFL and "work with young quarterbacks."

In February, the 36-year-old Vick announced he was retired from the NFL after not playing in 2016. ))