Shortly after the first Detroit Lions training camp session, the team issued something of a surprise transaction. Despite him participating in Wednesday’s practice session, offensive lineman Giovanni Manu was placed on the non-football injury list.

It was a puzzling move, since an NFI designation would necessarily preclude Manu from practicing. Lions head coach Dan Campbell cleared up some of the confusion ahead of Thursday’s practice session.

Campbell explained that Manu had a preexisting injury that he had failed to disclose. After the initial practice, Manu met wiht the team’s medical staff to have it checked. It was determined he needed to be placed on the NFI list. The exact injury was not disclosed by Campbell.

How long?

Campbell offered a grim assessment for the third-year lineman. “A period of time,” Campbell muttered. “12 weeks. 14 weeks.”

For a developmental project like Manu, missing the rest of training camp and several weeks, if not months, into the regular season seems to be an effective death knell for his future in Detroit. He was already up against a revamped depth chart on the offensive line, and Campbell had suggested in minicamp that Manu moving to guard might be his best option. Now, any positional switch or further technical growth is cut for at least three months, according to Campbell’s guesstimate timeline.