Coughlin was disappointed to see Locklear suffer what he would only describe as a "serious injury."
"I am not going to go into detail," Coughlin said. "But it will require surgery."
Coughlin was sensitive about Locklear's injury and losing a valuable contributor.
"I am sure that will take place at some point in time this week, maybe sooner than later," he said about Locklear going on IR. "We feel badly for Sean. Here's a guy that came in here that didn't know our system and played well for us and has been there when we needed him. We feel bad and are very upset about (the injury)."
Signed prior to this season for depth and experience, Locklear ended up starting 10-of-12 games at either right or left tackle. Locklear had his leg rolled up on from the side in the second half of the Giants' 17-16 loss to Washington.
David Diehl will now start at right tackle.
"I just wish him the best," guard Chris Snee said after the game. "Whatever recovery is ahead of (Locklear), I am not quite sure the extent of it. Just know it is not good. Good thing is David is healthy again and we need other guys to step up and fill roles, guys like (backup tackle James) Brewer will have to step up and take more of a swing role."