The Lions plan to sign former San Diego State offensive tackle Bryce Quigley Friday after hosting him for a workout Thursday.
The deal was pending as of Friday morning, but his agent, Rocky Arceneaux of Alliance Sports, said it would likely be official later today.
The Lions concluded mandatory minicamp with a full 90-man roster, so they would have to release a player to make room for Quigley, who went undrafted this year.
Quigley was a tight end for his first two years at San Diego State, but started the past two seasons at left tackle.
He tore a tendon in his left foot in the Aztecs' regular-season finale against UNLV in 2013, but played through the injury in their bowl game victory over Buffalo, which gave him less recovery time in advance of draft workouts.
He wasn't invited to the NFL combine, and at his pro day, he measured 6-foot-4, 324 pounds and had 19 reps on the 225-pounds bench press, according to NFLdraftscout.com.
Before coming to Detroit Thursday, Quigley visited the New York Giants, and he had other workouts scheduled.
The Lions are trying to find another free-agent gem at offensive tackle after LaAdrian Waddle started eight games at right tackle as a rookie from Texas Tech in 2013. Waddle is the favorite to win the full-time starting job this year.
Along with Waddle, the Lions have left tackle Riley Reiff, another starting right tackle candidate in veteran Corey Hilliard, rookie free agent Cornelius Lucas (Kansas State) and Michael Williams, a seventh-round pick out of Alabama in 2013 who converted from tight end this year.
Quigley will likely be competing with Lucas and Williams for a spot on the 53-man roster and could be a practice squad candidate if he doesn't make the team.
J.B. Shugarts, who went undrafted out of Ohio State in 2012, and A.J. Dalton, undrafted out of Robert Morris this year, were also on the minicamp roster.