O'Brien said Friday at the NFL Scouting Combine that he has sold his house in State College, but the purchaser was not his successor, James Franklin, who used to work on the same staff as O'Brien at Maryland.
The Texans have the No. 1 overall pick in the NFL draft, and Manziel, the former Texas A&M star, is one of the quarterbacks O'Brien is considering.
Manziel, who previously said it would be the worst decision they ever made if the Texans pass on him, is scheduled to meet with O'Brien Saturday.
I think it's a free country, said O'Brien, who was wearing jeans and warm-up top for his first Combine session with the media. I think he can say whatever he wants to say. I've enjoyed watching him on film just like these other quarterbacks. There are other quarterbacks in the draft, you know what I mean?
I know that there are three or four that are always mentioned, but I've watched a lot of quarterbacks.
A year ago, McGloin, a former walk-on who prospered in his one season of working with O'Brien in 2012, was not invited to the Combine and was not selected in the NFL Draft.
Yet McGloin earned a roster spot as a free agent with the Oakland Raiders and even started a few games.
I have a lot of respect for Matt, O'Brien said. We had a really fun year that first year at Penn State. He worked extremely hard to improve his own game and you have to give Matt all the credit.
While dealing heavy NCAA sanctions, O'Brien kept the Penn State program afloat despite the departure of some key players and guided the Nittany Lions to a 15-9 record in two his seasons.
He had just 65 scholarship players last season.
O'Brien took along six members of his Penn State staff to Houston, including Jim Bernhardt, director of football research, secondary coach John Butler, strength and conditioning coach Craig Fitzgerald, wide receivers coach Stan Hixon, running backs coach Charles London and assistant secondary coach Anthony Midget.
I brought some guys with me from Penn State that I really believe in, O'Brien said. Good coaches, smart guys, good communicators. They understand how we work, the hours that we work, the way we work, the way we meet, the style of play that we want to play and things like that.
Any time you can bring guys with you like that I think it definitely helps the transition.
Buffalo Bills coach Doug Marrone, who served as the best man in O'Brien's wedding, believes his friend with be a success in the NFL.
O'Brien served as Tom Brady's position coach and as the offensive coordinator of the New England Patriots prior to a accepting the head coaching job at Penn State in January 2012.
Like Marrone, O'Brien made the leap from college to become a head coach in the NFL.
Obviously, he's been with New England and he's been successful everywhere he's been, Marrone said. Like a lot of coaches in this league, he's got a great work ethic, but it's the same thing we're all here to make sure that we get great players.
It's a funny profession. I started off in Division III after I had gotten done playing and you grow up with a lot of people. There are a lot of coaches that I see here at the combine that I started with together going to clinics together.
Follow Ron Musselman on Twitter at @ronmusselman8