KANSAS CITY, Mo. – As spring gave way to summer, Graham Zusi looked like his old self again – ferocious on both sides of the ball, a threat to shoot as well as to distribute, a player who could dominate a match.

But as fall takes over the calendar and the final matches of the 2016 regular season loom, Zusi is in another no less familiar place: sidelined by a nagging injury, with no real timetable for his return.

Zusi could be back for Sporting Kansas City's next match as they try for a sixth straight postseason berth. Then again, the veteran winger might miss Saturday's away date with the San Jose Earthquakes (10:30 pm ET; MLS LIVE) with a calf strain that has already kept him out of Sporting's last two outings.

“I think it's an everyday situation,” manager Peter Vermes told reporters after Wednesday's training session. “It's not like he's got six more weeks. We just don't know.

“Personally, I just put it out of my head. When he's back, he's back, and then we'll see where he's at.”

Zusi picked up the calf strain while on US national team duty during the most recent round of World Cup qualifying. He has not played in any competition since going the full 90 in the Yanks' 6-0 away rout of St. Vincent and the Grenadines on Sept. 2.

And even when available and playing, Zusi hasn't been putting up DP-like numbers: one goal and four assists in 18 appearances, with just three goals and nine assists in league play since the start of 2015.

Even if he played in all four of Sporting's remaining regular-season matches, that would only give him 22 appearances this season – his fewest since 2010, when he made 19 appearances in his sophomore year with the then-Wizards.

That reality is a far cry from the hopes Sporting and their fans had for Zusi early this summer.

He was in solid form with the national team at this year's Copa América Centenario, smashing home a goal against Costa Rica in the second game of the group stage. After his return to MLS, a standout match against Columbus Crew SC on July 3 – in which he scored his only goal this year – raised hopes that Zusi was finally all the way back from the foot problems which plagued him in 2015.

“I don't know if you saw anything different. I just think you saw Graham Zusi,” Vermes said the week after the Columbus match. “I think he was man of the match. I think when you look at him, there was no answer for him in the game. There were times when he was making 50-yard runs with the ball, and they just couldn't stop him. He was unlucky to probably not score three goals, so to me that's who he is. That's the guy that I know.”

Zusi was still showing strong form in mid-August, just before leaving for the World Cup qualifiers, and had displayed increased versatility this season with several solid outings at right back. Then came the calf strain, and Zusi became one of a number of key contributors either slowed or taken out entirely by injury as Sporting try to cling to their spot just above the red line.

“When you miss some of your better players, it's hard to replace them,” Vermes said on Wednesday. “For any team in this league, it's hard. We've dealt with way too many injuries with our guys, and we don't have a consistent group on the field.

“That's a tough thing, I think, for any team. We've been dealing with it for too long, and that piece is very frustrating. It's a tough one.”