Kyle Shanahan won a combined 10 games during his first two seasons as head coach of the San Francisco 49ers. Now, the roster was in full rebuild mode during Year 1. The team lost its starting quarterback in Year 2.

Here we are in Shanahan's third season, and the 49ers have done something that the franchise hasn't been able to do in seven years — start 2-0.

This 49ers roster is deeper than any Shanahan has had during his time in Santa Clara. The last couple of seasons, you could make up excuses for all of the losing. The talent isn't there yet. There are too many injuries.

The excuses are over.

Shanahan has proved himself to be a great offensive mind and play-caller. But he's still trying to prove he can be a good head coach and this season will reveal a lot.

At least, that's what Peter King of NBC Sports says. He joined 95.7 The Game on Tuesday and was asked what the 49ers have to accomplish this season for everyone on the fence about Shanahan to finally be swayed and admit he is a good NFL head coach.

"Give him some time when he's got a good quarterback and more of a complete defense than he's had," King told Damon Bruce, Ray Ratto, and Matt Kolsky. "That's what he has right now. If at the end of this year, if Jimmy Garoppolo plays 16 weeks, and we get through this season and the 49ers are 6-10 or 7-9, then you have to start really asking yourself, do Kyle Shanahan and John Lynch know what they're doing?

"I don't think that's going to be the case, but again, you've got to let the season play out. I've thought all along that Kyle Shanahan was the right guy for this job, particularly with a young, impressionable, malleable quarterback like Jimmy Garoppolo, and I just think you've got to let him have the season."

The 49ers will play their first game this season at Levi's Stadium on Sunday with the visiting Pittsburgh Steelers trying to earn their first win of the year. It's a winnable matchup given the Steelers offense will be without quarterback Ben Roethlisberger, and the 49ers defense has looked much-improved compared to last season.

And, of course, you have the 49ers offense's impressive performance against the Cincinnati Bengals on Sunday.

"Just let [Shanahan] coach this team," King added. "See what happens by the end of this year. It doesn't make any sense to sort of take the temperature of him and how he's doing every week because, at the end of the year, I think you'll see all the pluses and the minuses, and you'll see if he's doing it right and if he's the guy for the long-term for this team."

You can listen to the entire conversation with King below.