PHOENIX -- When it comes to defensive tackle Louis Nix, Bill O'Brien's words aren't plentiful, but they're pointed.

During today's coaches' breakfast at the NFL league meetings, the Houston Texans coach addressed a variety of topics for his hour-long session.

Asked for an update on outside linebacker Jadeveon Clowney, guard Xavier Su'a-Filo and Nix, three 2014 draft picks who didn't play much last season for various reasons. He mentioned being pleased with Clowney's progress and work ethic. He called Su'a-Filo a hard worker who's in the office rehabbing every day O'Brien is. On Nix he said this:

"I have not seen Louis Nix," O'Brien said. "I don't know. He’s working out somewhere in Florida I guess. Haven’t seen him. But that’s their prerogative, so don’t read anything into that. When they show back up here for the offseason program, especially the younger players, the younger players need to be ready to roll. So hopefully he’s ready to go."

I asked what he needs to see change from last season in Nix.

"I would say the ability to make it through a practice," O'Brien said. "That would be the biggest thing I need to see."

This isn't the first time O'Brien has revealed some of his frustration with Nix's development. During the season he cited Nix's need to learn how to be a professional. To that end, Nix will have a great resource in the recently signed Vince Wilfork. O'Brien hopes he uses it.

"If you're a young player in that defensive line room and you've got J.J. Watt and Vince Wilfork in that room, you'd be crazy not to kind of follow those guys around," O'Brien said. "Now you don't have to try and be like them, but I think you'd be nuts if you didn't use those guys as examples. You've got the best defensive player in the league, and then you've got this guy who's going to go down as one of the best interior linemen to ever play the game, and you're a first or second-year player in that room. You're not going to follow that example?

"It's going to be a great opportunity for Louis Nix."