KANSAS CITY, Mo. – C.J. Sapong is back training with his Sporting Kansas City teammates, but it could be some time before the forward is match-ready again as he continues his recovery from neck and back soreness.

“He did a little bit, got involved in some early stages,” manager Peter Vermes told reporters after Tuesday's training session. “After that, we pulled him off and did some transition stuff with him. He's still got a little time before he gets back into the group.”

Sapong is listed as questionable for Sunday's home match against Eastern Conference leaders Columbus (3 pm CT, NBCSN, 810 WHB, La Gran D 1340). Vermes said right winger Sal Zizzo will miss that match with a groin strain he picked up in last weekend's 2-0 loss at New England.

Zizzo is not expected to be out for long, though.

“I don't think it's as bad as everyone thought,” Vermes said. “He was smart. He felt it, and he got out. He'll be back soon.”

Sapong started Sporting's first two league matches this year but has not played since coming off the bench in a 1-0 win over San Jose on March 22.

“It was kind of short,” he said after Tuesday's session, his first with the full side since he was sidelined. “But as the days go by, I'll be able to do more and more, get that feeling again.”

The soreness was the result of cumulative strain on his neck and back, Sapong said.

“I just wanted to take some time to get it to equilibrium, back to the point where one small collision wouldn't make it flare up again,” he said, “Just the way I play, there are many collisions.

"Perhaps early, I just was able to pawn it off as random soreness or bruising, but ultimately it got to the point where we realized it was repeating too much, and I needed to take the necessary precautions to get it to the level where it won't flare up too easily.”

Steve Brisendine covers Sporting Kansas City for MLSsoccer.com.