The U.S. assistants under Bruce Arena, right, included, from left, Matt Reis, Pat Noonan, Dave Sarachan and Kenny Arena. (Andrew Fielding/USA Today Sports)

Until the U.S. Soccer Federation hires a permanent replacement in the coming months, the assistants who worked under ousted men’s national team coach Bruce Arena are overseeing the rebuild of the program. But because it’s a temporary assignment, with contracts slated to expire at the end of March, the staff has permission to pursue long-term gigs elsewhere.

And as the national team gathers for winter camp this week, at least two members are preparing to move to MLS clubs.

The Insider has learned Pat Noonan is on the verge of becoming a Philadelphia Union assistant coach, and Kenny Arena will join Los Angeles FC’s technical staff.

Also, Dave Sarachan — the head coach for the November friendly at Portugal and this month’s training camp — had a preliminary conversation with Saint Louis University about its head coaching vacancy, multiple sources said. An intermediary arranged it. However, the Billikens are seeking a coach directly from the NCAA ranks. The university did not renew Mike McGinty’s contract after eight seasons.

With MLS teams preparing for the scouting combine Jan. 11-17 and college draft Jan. 19, it seems unlikely Noonan and Arena would remain with the U.S. squad this month, which includes a Jan. 28 friendly vs. Bosnia in Carson, Calif. U.S. players will report to camp Wednesday at StubHub Center and begin workouts Thursday.

Noonan, 37, reportedly interviewed for the New England Revolution’s head coaching job in the fall. Before joining Arena’s U.S. staff, the former MLS attacker worked for Arena at the Los Angeles Galaxy. He is a contemporary of Union Coach Jim Curtin and Philadelphia technical director Chris Albright, both 38. Noonan would fill a slot vacated by Mike Sorber, who last month joined Bob Bradley’s LAFC staff.

Last month, Noonan completed the year-long Pro License Coaching Course, “the highest form of soccer licensing offered in North America,” according to the USSF.

Kenny Arena, who turns 37 next month, was an assistant on his father’s staff with both the Galaxy and U.S. squad. His prior experience came as a head coach at Florida International University and an assistant at Virginia (his alma mater), George Mason and UCLA. He and Bradley have known one another for Arena’s entire life; Bradley and Bruce Arena worked together at the University of Virginia and D.C. United.

LAFC also has hired goalkeepers coach Zak Abdel, who worked for Bradley on the U.S. and Egyptian national teams.

The other members of the U.S. staff are Matt Reis and Richie Williams.