Kansas City Chiefs quarterback Alex Smith has admitted that he was surprised to see the departure of Jim Harbaugh at his former club the San Francisco 49ers.

Smith played under Harbaugh at the 49ers for two seasons before he was traded to the Chiefs, and he has conceded that he was shocked by the 51-year-old's exit because of his success in his four years at the club.

Meanwhile, the 30-year-old has also giving his backing to Jim Tomsula as Harbaugh's replacement at the club after previously working with him in the 2010 campaign.

"I think for me, it's still just tough to believe all those guys are gone, all that turnover," Smith told the San Jose Mercury News.

"There were a lot of ballgames that got won over the last few years, but for whatever reason, they couldn't make it work. I don't know.

"I wish coach Tomsula well. I wish him the best. I know he has the ability to be a head coach. He's a good man, a really good coach. I'm pulling for him."

Smith played for the 49ers for eight seasons after being selected with the first overall pick in the 2005 Draft.