Tamba Hali’s normal Sunday routine this time of year is to make the drive to Arrowhead Stadium, where he joins his teammates in preparation for the day’s game.

He clearly didn’t know what to do with himself last week.

“(On) Sunday, you have a routine. You have things you do,” the Pro Bowl linebacker said, slowly getting aggravated at the memory. “It was a little different waking up in the morning and watching a bunch of TV and walking around. It’s not what I’m used to. But I was able to get through it.

“Being away from our team wasn’t something I liked.”

Hali rejoined the Chiefs at practice Wednesday, his one-game suspension for an undisclosed violation of the NFL’s substance-abuse policy finished. He will play in Sunday’s game against the Bills in Buffalo.

His first order of public business was to apologize to the league and the Hunt family, owners of the Chiefs.

“This is not the type of light they want the organization to be in,” he said. “I’m truly sorry for the embarrassment. I just want to move forward and get better as a team and as an individual.”

The Chiefs, who were picked apart by the Falcons without Hali on the field on Sunday, were more than ready to forgive him.

“Tamba has already made his apologies,” linebacker Derrick Johnson said. “We stick by Tamba all the way. He’s one of our brothers, one of our family members. We know he’s all-in with us, so we just can’t wait for him to go out and sell his heart out there on Sunday.”

Hali has been the Chiefs’ leading pass rusher in each of the past four seasons. He led the AFC with 141/2 sacks in 2010 and played in the Pro Bowl for the first time last year after getting 12 sacks.

The Chiefs had trouble putting pressure on Atlanta quarterback Matt Ryan. Their other starting outside linebacker, Justin Houston, had a sack, but Ryan mostly had adequate time to make his passes.

“I hope I see the effort he gives on every play (and) what he brings to the table as far as pass rush goes,” Chiefs coach Romeo Crennel said. “I hope he hasn’t forgotten anything and that he can step right in and move right along.

“The way he approaches the game and the way he plays down in and down out, that impacts the guys around him. They want to play up to the level he plays. When you get guys playing up to the level that he plays, then you can lift the team.”

Hali had missed just one game in his first six seasons with the Chiefs, a 2008 contest against New Orleans. That was for injury reasons.

Hali was able to work out at the Chiefs’ practice facility last week and attend team meetings, but he was not allowed to practice.

Since he couldn’t play or be on the sideline for the Atlanta game, he stayed home with his mother and daughter.

“It wasn’t fun screaming at the TV,” he said. “We played a good team. It’s always frustrating when I can’t be out there or any of the other players can’t be out there to contribute. They played as best they (could).

“I don’t think we played bad. I think that team we played (against) was able to execute. We just need to be on top of our game and that was something that was lacking.”

Having already lost one at home, the Buffalo game is crucial for the Chiefs. But the Bills are a similarly desperate team, having lost their opener by 20 points to the Jets.

“I’m sure (the Bills) are desperate and want to win,” Hali said. “We want to win. The guys in the locker room, we’re not too pleased with the result last week.

“Coming into this game, it will be a lot more emotional. Then we’ll have to settle down and play a lot more poised and get a win out there.”