The Nittany Lions lost strength and conditioning coach Craig Fitzgerald and his two assistants, Dwight Galt IV and Sean Hayes, all of whom resigned. Special assistant to the head coach Jim Bernhardt, a longtime friend of O'Brien's, also is out.
While the Texans did not make any official announcement, multiple reports have all eight former Penn State employees joining O'Brien in Houston. Butler and Fitzgerald are graduates of La Salle College High School.
The moves leave just three assistant coaches - interim head coach Larry Johnson (defensive line), Mac McWhorter (offensive line) and John Strollo (tight ends) - on duty at the Lasch Football Building on campus. Their primary task is to keep all 19 commitments to the Class of 2014 with the program.
Johnson has applied for the head coaching job but has yet to interview as of Monday. Athletic director Dave Joyner, chair of the search committee, said last week that Johnson "certainly will get every strong consideration of someone of his stature."
Players continued to support Johnson on Twitter. Running back Bill Belton, who starred at Winslow Township High School in South Jersey, tweeted, "Why is Coach Johnson not hired as the HC yet? Great choice and provides amazing leadership!"
Johnson also took to Twitter Monday, saying, "Humbled by the many words of support received from Nittany Nation and players. Honored to help bridge the gap as we move forward."
The brunt of the head coaching attention remained focused on two candidates who reportedly interviewed on Sunday – former Tennessee Titans head coach Mike Munchak and Vanderbilt coach James Franklin.
Munchak, a former Nittany Lions player, denied Sunday night to the Tennessean that he interviewed but ESPN's Chris Mortensen tweeted later that Munchak "absolutely" interviewed with Penn State.
Franklin, whom the NFL Network said would interview with the Washington Redskins, spent Monday with ESPN at the BCS championship game in Pasadena, Calif., but did not address questions about his immediate future.
"It's just a tremendous compliment to our program and what's going on right now," said Franklin, who has led Vanderbilt to three straight bowl games.
Miami coach Al Golden was said to have interviewed on Saturday but released a statement Sunday insisting he was "not a candidate" to be a coach anywhere else. He evaded questions Monday about Penn State at a news conference, and would not say if he interviewed or considered leaving to return to his alma mater.
"There are universities that have expressed interest the past couple of years," Golden said as quoted by the Miami Herald. "I have not addressed them and I'm not going to start now. It's flattering . . . other people expressing interest in us."