METAIRIE, La. (AP) -- Saints running back C.J. Spiller says he isn't being coy when he declines to pinpoint when he'll play in his first game this season.

Spiller, who missed all four preseason games and last weekend's regular season opener because of minor knee surgery, has now completed two practices this week, albeit on a limited basis. If he was certain he'd be ready to play by Sunday against Tampa Bay, he said, he wouldn't try to hide it simply to preserve an element of surprise.

"I ain't into surprises. I don't surprise nobody. I want you to see me coming full speed," Spiller said playfully after Thursday's practice. "It ain't Halloween, baby. Trick or treat. I'm coming full speed at you. Trust me, you'll know when 28 is out there."

Spiller, who built a reputation as an explosive play-maker in Buffalo, was one of New Orleans' more prized acquisitions in free agency this past offseason. The hope was his speed and versatility out of the backfield would give New Orleans' offense some of the dynamism it seemed to have lost since speedster Darren Sproles was traded to Philadelphia.

If Spiller doesn't play against the Buccaneers, it should not be much longer, he said.

"I'm getting there. I guess you can say that," Spiller said. "It feels good. We'll see how things continue to progress. The biggest thing is keeping the line of communication with me, the training staff, and (coaches), letting them know how I feel."

"You can feel good one day and feel terrible the next. So today, that's the only day I'm focused on, and today I feel good," he added.

The Saints didn't exactly struggle to move the ball without Spiller last week at Arizona, surpassing 400 yards. But they settled for four field goals to go with only one touchdown in a 31-19 loss.

Spiller said he is eager to contribute, adding that he remained focused on learning the Saints' offense during his rehabilitation.

"It wasn't like I was just sitting on the couch eating potato chips. I was in the playbook, I was watching film. I was staying there mentally," Spiller said. "Obviously I wasn't in the huddle hearing the play call. That's the only thing that is negative. Getting with a new quarterback and seeing how he calls the plays, that's the thing you miss out on -- and timing.

"I don't think it's going to be confusing when I come back for the play calling because I was in the playbook," he added. "I stayed sharp."

While Spiller is showing signs of returning sooner than later, several key defensive players missed practice on Thursday. One of them was Jairus Byrd, who has not practiced once because of a knee injury since training camp began. Also out was linebacker Dannell Ellerbe, who injured his toe in New Orleans first preseason game more than a month ago, and cornerback Keenan Lewis, who hurt his hip in the Saints' third preseason game.