Real Clear Politics reports that Fox News White House correspondent Major Garrett is trading in the briefing room for the studio, serving as guest host of “Fox News Sunday” this weekend July 4.

RCP speculates that it could be something of a tryout for Garrett:

Though Garrett is simply filling on a holiday weekend, his peformance will invariably be seen by some as a potential audition for a shot at the host chair when Chris Wallace, now 62, decides to call it quits at some point in the future.

Meanwhile, Chris Wallace, whose seat Garrett will be filling, had a few things to say on “Imus in the Morning” about Helen Thomas‘ currently vacant seat in the White House briefing room.

According to Think Progress, Wallace told Don Imus:

“If this were to happen because obviously she was very far to the left wing and if her seat were to be taken by Fox News it would just be kind of poetic justice,” said Wallace. Imus quickly noticed that Wallace was all but saying that Fox was right wing and gave Wallace the opportunity to walk back his comment.

Wallace did walk back his comments a bit, but Imus still advised Wallace to “say hi to Roger [Ailes] when he calls you.”