It was supposed to be a basic ultrasound, trying to determine why O'Brian White's left leg was numb.

White, the new striker for Seattle Sounders FC, never left the hospital that April day. The doctor administering the ultrasound noticed something that didn't show on a previous MRI: a blood clot in the lower left leg.

Suddenly, White's entire season was in question, a setback all the more troubling for the team because midfielder Steve Zakuani was lost for the year with a broken leg.

Now, White could return as early as this weekend when the Sounders host Colorado. If White doesn't make his return against the Rapids, the Jamaican forward will likely play Wednesday when the Sounders host Premier League champion Manchester United in an exhibition game.

"They've been monitoring everything I do," he said. "It's not like I'm coming back in rushed time," White said this week. "The doctor says everything is good. I think it's time. I feel good. I feel confident playing back."

He'll be joining a team on a roll. Seattle rallied twice in the second half at Portland last Sunday, getting the winner on Osvaldo Alonso's penalty kick goal in the 84th minute of a 3-2 win. Seattle is unbeaten in eight straight league matches, the longest streak in the club's three-year history.

Seattle also kept its U.S. Open Cup streak going with a 3-1 win over the Los Angeles Galaxy in the quarterfinals Wednesday night. The two-time defending champion Sounders will host FC Dallas on Aug. 30 in the semifinals.

But first come the Rapids on Saturday.

It was early in Seattle's 1-0 victory over Colorado on April 22 tin which Zakuani was lost for the season, the result of what Zakuani called a "really bad tackle" by Colorado's Brian Mullan. In the third minute, Mullan barged into Zakuani near the sideline. Zakuani's right leg was caught underneath him by the force of Mullan's tackle, breaking his tibia and fibula.

Mullan's 10-game suspension expired at the end of June and he played in the Rapids' 2-1 win over Vancouver last weekend. It's unclear if Mullan will make the trip or play in Seattle.

Lost in the aftermath of Zakuani's injury were the issues with White's leg.

White first became concerned during training before Seattle's game at Colorado. He noticed that numbness in his leg would come and go, but attributed it to another chilly day in the Pacific Northwest.

The Sounders' medical staff played it safe and suggested an MRI. When nothing showed on the scan, he was cleared to face the Rapids and played all 90 minutes of the victory. After returning to Seattle, the numbness became more consistent. That's when an ultrasound was ordered and, eventually, surgery.

White had missed time in college with a torn knee ligament, but understood the seriousness of a blood clot in his leg.

"This time was more like it changed the way you feel about everything," White said. "Anything could happen at any given time. Good thing the doctors figured it out early."

The Sounders learned early on that White wouldn't miss the rest of the season, but were unsure exactly when he would get back. If White needed to stay on a blood thinner to alleviate clotting, then his return would have been delayed because of a need to avoid significant contact.

"Once that decision was made, which was made pretty early on, that obviously got our hopes up," Seattle coach Sigi Schmid said.

White spent the first month of the season as Seattle's best scoring threat. White, acquired in a trade with the Vancouver Whitecaps, was tied for the team lead in goals when sidelined.

His presence will also help as Seattle gets into its busiest part of the schedule with games in the CONCACAF Champions League along with MLS matches.

"I feel so much better. I feel sharper," White said. "The more I play the sharper I get. ... Once I get a couple of games in I'll be close to getting back to myself."