When Miguel Ibarra called to ask former college soccer teammate Amani Walker about signing with the Minnesota Stars FC this season, Walker didn't hesitate.

"I was like, 'Please come here,' " Walker said. "He's the fastest guy I've played with in a very long time."

Ibarra and Walker scored goals as the No. 6 seed Stars upset No. 3 seed Puerto Rico 2-1 last weekend and began their push toward a second consecutive North American Soccer League championship.

The semifinal series against No. 1 seed San Antonio begins at 7:30 p.m. Saturday at Blaine's National Sports Center. The two-game total goal series will be decided Oct. 14 at San Antonio.

Ibarra and Walker, who played together one season at California-Irvine, said they believe the Stars can continue another unlikely playoff run. San Antonio (13-8-7) led the NASL in goals scored (46) and fewest goals allowed (27).

"San Antonio is a solid team through and through -- we recognize that and I think they recognize now that we're a decent team," Walker said.

Minnesota (9-11-9) did not beat the Scorpions in four meetings this season. But the teams' two draws came as the Scorpions sputtered in September. They won only one of their final six regular-season matches.

"We dominated a lot of those games, but we couldn't get the ball in," Ibarra said. "Now we're starting to score and get our groove."

Ibarra and Walker are roommates off the field who ride to and from practice together. On the field they are an odd couple. Walker (6 feet 2) and Ibarra (5-7) use their physical attributes in different ways. Walker's height makes him strong around the goal and in the air.

Ibarra?

"He has great speed and great ability to hold the ball and make something happen," Walker said. "He's tiny and crazy."

David La Vaque • 612-673-7574