John Clayton, a host with ESPN Radio, joined KNBR on Thursday and discussed the NFC West. He is among those who believe the San Francisco 49ers are primed to be significantly improved this season.

"The two teams that I think are going to make the biggest rises are going to be San Francisco and Jacksonville," Clayton said on the "Murph and Mac" show.

Clayton does note that if fans are hoping for a playoff appearance, they should temper their expectations.

The 49ers bolstered their pass rush this offseason by adding veteran Dee Ford and rookie Nick Bosa along the edges to complement interior mainstay, DeForest Buckner. The team has also dealt with a significant number of injuries during Kyle Shanahan's first two seasons as head coach.

Clayton adds, "The key for the 49ers, because, again, they're one of the most improved defensive lines in football, their pass rush is going to improve dramatically — the question is going to be depth and where they are with injuries … If the team is going to be healthy, it should be able to get to eight or nine wins."

San Francisco is 10-22 over the past two seasons and hasn't finished a season at .500 or better since 2014.

Still, it could be a tough climb for the 49ers, who won just four games last year. Clayton still envisions both the Los Angeles Rams and Seattle Seahawks being significantly better than Shanahan's squad. He does, however, feel the Rams will suffer a drop-off of about two games from last season. Much of that has to do with the health concerns surrounding running back Todd Gurley and the losses along the offensive line.

"And then Andrew Whitworth, who has been as good as any left tackle in football, is 37," Clayton added. "At some point, age has to catch up to him."

Clayton also doesn't believe the Rams have improved on defense.

While the 49ers have improved their pass rush this offseason, the Seahawks failed to do so, says Clayton. Seattle signed Ziggy Ansah to fill the void of Frank Clark, who was traded to the Kansas City Chiefs. The team also drafted defensive end L.J. Collier.

"You can honestly say, at the moment, and you'll appreciate this — the only proven pass rusher is Cassius Marsh, and he had [five]-and-a-half sacks last year," Clayton said. "It's a big question mark."

Marsh, of course, spent two-and-a-half seasons with the 49ers before rejoining the Seahawks in April.

As the Seattle defense looks to develop, Clayton believes the offense is good enough to carry the team while the rebuild continues.

You can listen to the entire conversation with Clayton below.