Steelers starting center Fernando Velasco, who did an admirable job filling in for All-Pro Maurkice Pouncey with Pouncey on injured reserve, has been lost for the season because of an Achilles' tear, according to a league source, The team will be signing depth replacements. Pittsburgh suffered several key injuries in the loss at Baltimore on Thursday night, which could see them miss the postseason. Running back Le'Veon Bell suffered a concussion on a goal-line hit late in the game, and while he is progressing well, it is still far too early to determine his status for Week 14 with a concussion protocol to follow next week.