ALAMEDA – Kelechi Osemele was really excited about returning to Baltimore. He played four seasons with the Ravens and was upset they didn’t try harder to retain him before the Raiders coaxed him to switch coasts.

He had to keep emotions in check during that Week 4 win against his old teammates.

Sean Smith won’t experience something similar on Sunday against the Kansas City Chiefs. The veteran cornerback will face a Chiefs team he represented the past three seasons before signing a four-year, $38 million contract.

That doesn’t add meaning to this next tilt.

“Why would it? It’s business,” Smith said before Wednesday’s practice. “It’s the NFL. It’s not my first time doing this. I’ve switched teams before. You put on a new helmet, line up and go to work.”

Smith played in Miami four seasons before moving to Kansas City. Playing in different spots makes these instances easier, though Smith doesn’t let emotion creep into his work.

“We’re trying to go 1-0 this week,” Smith said. “It’s a division game, so it has some importance, but there’s nothing extra special for me there.”

Smith will have friend across the sideline, including young Chiefs cornerback Marcus Peters and quarterback Alex Smith.

Smith as respect for his former quarterback, and knows how good Alex Smith can be.

“It’s not always pretty, with 300 yards and four touchdowns, but Alex always gets the job done,” Sean Smith said. "When that team needs a big play, he may run or throw or break a tackle and make a play. He’s always going to make sure his team has a shot late in the game.”

Alex Smith must fare well against his old friend and teammate.

“It’s always interesting any time you go against corners that you obviously played with for a long time," Alex Smith said in a conference call. "Sean and I, obviously both going to Utah and then played here together for three years. We have a really good relationship. He and I used to always go back and forth in the locker room. It’ll be interesting to go against him. It’s very similar to playing with Brandon Flowers here and him going to San Diego. It always makes for an interesting matchup. You know each other well. You went against him a lot in all of OTAs and camp and things like that. It’ll be good. He’s obviously a really, really good player. It’ll be a good matchup.”

There was no bulletin board material in Smith’s media scrum, which is how he likes it going up against an old team.

“I wish them the best of luck,” Smith said, “except for Sunday.”