KANSAS CITY, Mo. – Graham Zusi and Sporting Kansas City are still looking for answers, as the Designated Player winger continues to play through the pain in his right foot.

A stress fracture sidelined the US international through much of the preseason – and while he has gone deep into both of Sporting's first two matches, he has felt (and shown) the lingering effects of the injury each time out.

“He's still coming back from that injury, and it's still a work in progress here,” manager Peter Vermes told reporters on Tuesday. “He's trying to get to a point where he has no pain at all, and he still has pain as the game wears on. So it's something that we're still trying to work with at the moment.”

Vermes said he has seen a noticeable difference in Zusi's play after halftime, when players cool down and then have to get back up to speed quickly. Zusi agreed with that assessment.

“It's a game of two halves for me,” he told reporters on Tuesday as Sporting get set to play host to the Portland Timbers on Saturday (8:30 pm ET; MLS LIVE).

The decision as to when Zusi needs to come out of a match is the responsibility of both the player and the coaching staff, Vermes said.

“Sometimes you can overdo it, and I sort of have to be the barometer for him at times,” he said. “That's the way I am with all of our players. But when you spend the amount of time that I have with Zus over the years, you kind of know.”

Zusi made a follow-up visit to a physician earlier this week, Vermes said, and the findings were positive – in part.

“The good thing is that nothing's changed negatively,” said Vermes, who has said that overuse in 2014 – between MLS play and the 2014 World Cup – was to blame for Zusi's injury. “It hasn't gone the opposite way. … We're going to try a couple of different things with him, but he's still got pain.”

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Vermes has repeatedly acknowledged a cautious approach to bringing players back from injury, but said he deals with each situation differently.

“It's not, 'pain free.’ It's what the person can tolerate,” he said. “And this is not a muscle injury. It's a different type of injury. It's not where the guy is making it worse at the moment. It's just whether or not the pain is starting to dissipate.”

Zusi said he hoped the solution would be found soon, adding that it could be something as simple as switching to a special boot on that foot.

“It's not a pride thing for me” to play through pain, he said. “I just want to help out my team the best that I can.”

Steve Brisendine covers Sporting Kansas City for MLSsoccer.com.