Minnesota United coach Adrian Heath said after his team's preseason opener Saturday that he remains "optimistic" it can obtain attacking midfielder Emanuel Reynoso from his Boca Juniors club in Argentina.

Heath also said he's hopeful newly signed Paraguayan striker Luis Amarilla will, barring immigration complications, arrive in Minnesota and train with his new teammates in Blaine after the team returns next Saturday from training in Florida.

Heath said so on a day when starting left back Chase Gasper made his U.S. men's national team debut when he came on in the 77th minute of a 1-0 victory over Costa Rica in Carson, Calif., and his MLS team defeated Florida International University 5-0 in its first of three games/scrimmages in Melbourne, Fla., in the coming week.

Heath said United's attempt to sign Reynoso – who, like Amarilla, is 24 years old – is "still very much in the pipeline." United technical director Mark Watson traveled to Buenos Aires for several days before returning early last week.

Heath also said the team still is "actively working" to obtain another center back as well.

Striker Mason Toye scored twice in the preseason opener, while Kevin Molino, newcomer Marlon Hairston and rookie Andrew Booth scored once each. Heath called himself "really pleased with some of our play" and most importantly declared injury-free.

The victory over a collegiate squad – the first of three training games/scrimmages the team will play in Florida – was "a really good, workmanlike performance," Heath said, He praised the ball movement between midfielders Molino, Robin Lod, Ethan Finlay, Ozzie Alonso and Jan Gregus that led to those three goals by Toye and Molino.

United played separate 11s, each for a half.

The first half's 11: Goalkeeper Tyler Miller, defenders Hassani Dotson, Michael Boxall, Ike Opara and Romain Metanire, midfielders Gregus, Alonso, Lod, Molino and Finlay with striker Toye out front.

The second half's 11: Keeper Gregg Ranjitsingh (Dayne St. Clair substituted in), Wyatt Omsberg, rookie Noah Billingsley and two trialists at defender, midfielders Thomas Chacon, James Musa, Jacori Hayes, Booth and Marlon Hairston and rookie Matthew Bentley out front.

Call Heath impressed with his four goalkeepers, the three aforementioned and 15-year-old homegrown player Fred Emmings. Heath suggested it's the best group of goalkeepers in MLS.

"I really believe that," he said. "I think we've got the next U.S. (national) team goalkeeper (Miller). Greg has come in and done great. Dayne is getting better by the day, so they're a really good core group to work with. And then we've got Fred Emmings as the young boy to work with. The four goalkeepers have been really outstanding. I'm delighted with them."

Gasper completed his participation in the national team's January camp with Saturday's game debut after he had been sidelined for 10 days because of a lower-leg injury.

"He had a good camp, they're pleased with him," Heath said. "I'm looking forward to getting him back here. He had a great full season. Now we have to work with him again and see if he can be even better."

Heath also praised players' spirit and performance during these training days filled with two or three sessions a day.

"The mood in camp is fantastic, the best since I've been here," he said. "They've worked so hard, dragging each other through these sessions, no moaning. Everyone is getting on with it, dragging each other through."