MACOMB, Ill. -- Rams rookie offensive guard Scott Tercero, the team's sixth-round pick, will be sidelined an estimated six weeks because of a knee injury.
Tercero, injured in the first of two workouts Friday, will undergo surgery Saturday. Tercero first hurt his knee lifting weights last week, and tore cartilage when he slipped and fell during a non-contact drill.
Wide receiver Mike Furrey, an offseason pickup from Northern Iowa who has opened eyes early in camp, will be out perhaps two weeks due to a mild high ankle sprain.
"I really like this young man and I think he's got a future with us," coach Mike Martz said. "We've just got to make sure when he comes back he's ready."
Offensive tackle John St. Clair missed the afternoon full-pad workout after becoming dehydrated earlier in the day.
Second-round pick Pisa Tinoisamoa spent his first day on the practice field after signing on Thursday. He missed the first two workouts.
"I'm just excited to be out there and I'm glad everything is done," Tinoisamoa said.
Tinoisamoa is projected as a starting outside linebacker opposite Tommy Polley, with Robert Thomas, the team's first-round pick last year, moving to middle linebacker.
Tinoisamoa arrived at training camp late Thursday night after getting ticketed for speeding on the 3 1/2-hour drive from St. Louis to western Illinois.