Jeff Allen could be making a move to left tackle for the Texans after Sunday's game in Nashville.
"I think that we'll see where we are relative to injuries and all those things, but yeah I could see him being our left tackle again," O'Brien said Monday.
Against the Tennessee Titans, Allen saw his first action at left tackle with starter Chris Clark on injured reserve. Since he signed with Houston in 2016, Allen has played right guard in each of his 23 starts. The six-year veteran has seen action at left tackle and left guard during his four seasons with the Kansas City Chiefs (2012-15).
"I felt pretty comfortable," Allen said. "Obviously, I still have some work to do. I was a little rusty out there."
Greg Mancz, who started all 16 games last year at center, stepped in at right guard. Allen was flagged for three false starts on the Texans final offensive series, but O'Brien did not believe the flags were his fault.
"I thought Jeff Allen did a decent job at left tackle," O'Brien said. "The false starts were not all his fault. We were in a couple different cadences there and I've got to do a better job of coaching that. I wouldn't put that on Jeff Allen, those false starts. I thought Jeff played good. I thought Xavier (Su'a-Filo) probably played one of his better games. I thought Nick (Martin) did some good things on the inside, all of them in pass pro. Breno (Giacomini) plays a very tough, tough veteran leadership type game every week and I thought that Mancz had a solid day."
The modified Texans o-line had success in pass protection in the 24-13 loss to the Titans, gaining 384 total net yards on offense. Houston's 331 passing yards were the second-most in a game this season (367 vs. Seattle in Week 8). The Texans rushed for just 53 yards against a stingy Titans run defense, but O'Brien sees potential in the offensive line's performance.
"I can't say that that'll be the line every week but I thought that those guys played well and I would anticipate that that's probably the offensive line moving forward here for the next few weeks," O'Brien said.
The Texans return to NRG Stadium after back-to-back road games to host the San Francisco 49ers in Week 14. Kickoff is set for Sunday at noon CT on FOX and SportsRadio 610.
The Texans faced AFC South rival Tennessee in Nashville in Week 13.