Offense: Who Stays? Who Goes?

With yesterday's reports that Washington assistant coaches Johnny Nansen and Keith Heyward will be joining new head coach Steve Sarkisian's USC coaching staff, it is official that change is coming.

Typically, when a new head coach is hired, the retention rate is very low, but sometimes exceptional coaches can make a good impression and limit the amount of staff turnover.

For example, Ed Orgeron was a carryover on Pete Carroll's staff from Paul Hackett's tenure at the helm of the Trojans. It was also reported today that USC receivers coach Tee Martin will be one of those exceptions.

But what about the rest of the offensive staff? Who stays? Who goes?

Here's our quick assessment of the remaining coaches chances of sticking around:

Clay Helton -- Interim Head Coach/Offensive Coordinator/Quarterbacks

What a crazy season Clay Helton has had! Helton went from a non-play-calling offensive coordinator under Lane Kiffin to actually calling plays under Orgeron. Now he's been named the interim head coach for the bowl game, whichever bowl game that may be, and could likely be out of a job following that game.

Hired by Kiffin his first season at USC after 10 years with Memphis, Helton advanced from quarterbacks coach to the passing game coordinator last season before being promoted to offensive coordinator this year. But that name was in title only until Kiffin was dismissed. With Helton calling plays, USC averaged 399.8 yards of total offense per game and 6.2 yards per play.

If Helton was to be retained, he'd be forced to return to being an eye-in-the-sky, help-out-with-the-gameplan coordinator rather than being a play caller since Sarkisian has called his own plays since becoming a head coach.

Retention Potential: Unlikely

Tommie Robinson -- Passing Game Coordinator/Running Backs

The odds might look dim for the former Troy State safety after the hiring of Nansen, who was the running backs coach at Washington. But that's not necessarily the case. It could easily play out that way, but if Robinson can make the same impression he made on Orgeron, who called him the best running backs coach he's been around, he might stay on in the same capacity under Sarkisian.

Depending on how the rest of the staff shakes out, Nansen could fill a variety of roles thanks to his diverse background. Prior to being hired by Sarkisian in Washington, Nansen coached defensive line, linebackers and special teams at Idaho. He originally was the Huskies' defensive line coach, but moved to running backs after the hire of Tosh Lupoi in 2012.

Robinson has six years of NFL experience that are also valuable in recruiting -- something one source said Robinson was told by Pat Haden to continue doing, so don't count him out just yet.

Retention Potential: Not So Fast, My Friend

James Cregg -- Offensive Line

Cregg just spent his fourth season as the offensive line coach at USC after coming over with Orgeron and the Kiffins from Tennessee. USC's offensive lines were a strength for the Trojans when top 10 picks Tyron Smith and Matt Kalil were manning the left tackle spot, but struggled the last season.

The unit struggled enough that a second offensive line coach, Mike Summers, was brought in before the 2013 season. The offense improved from 151 to 174 rushing yards, but that included performances of 30 yards against Utah and 23 versus Stanford this year. The line also allowed 33 sacks this season after giving up only 17 in 2012.

Retention Potential: He Gone!

Mike Summers -- Running Game Coordinator/Offensive Line

Like Robinson, Mike Summers joined the USC staff prior to this tumultuous season. He also has a strong history working with a variety of schools before following Tee Martin from Kentucky in the offseason (though he had accepted a position with Western Kentucky prior to joining USC in January).

As offensive line coach and running game coordinator, we're willing to give Summers a little more credit for the rushing success than Cregg this season. But after a season at USC is the former Oregon State assistant head coach /offensive coordinator ready to try his luck somewhere else? Summers is the guy I'd turn the line over to full time and let him go to work like he did under Bobby Petrino at Louisville when the Cardinals went to four consecutive bowls behind Summers' lines, culminating in the 2006 Orange Bowl.

Retention Potential: He'll Have Offers. Will USC Be One?