The NFC West champions used the first pick in the 2005 draft to select the quarterback, but traded him to the Chiefs earlier this year after he lost the starting job to Colin Kaepernick.
Speaking at a press conference, the 49ers' offensive co-ordinator said: "He's a nameless, faceless opponent. I wish him nothing but the best. He's a fine, fine competitor and quarterback."
Offensive lineman Daniel Kilgore added: "The one thing I have thought about is how much hotter it's going to be. But, no, it's going to be awkward to see him in another uniform. Alex is a good dude, a good friend of mine.
"It's going to be one of those deals where you see a friend and just like any other team, you congratulate him and wish him luck for the season. I know he'll do well anywhere he goes. We've got a quarterback now that will do well for himself, too."
Both teams lost their opening pre-season games earlier this week.