Major League Soccer's World Cup break really isn't much of a break at all. The league is taking this weekend off in theory, but 13 teams are in U.S. Open Cup's round of 16 games. So it will feel like a full slate.

The Union are one of those teams, but they should feel plenty refreshed when they host the New York Red Bulls on Saturday night (7 p.m., live stream at ussoccer.com). After playing their fifth game in 14 days last Friday, the team has had eight days to rest and rehab injuries.

Union manager Jim Curtin didn't want to call his team fatigued after the stretch-ending 2-0 loss to Toronto FC, but players were a half-step slow at both ends of the field. Now the proverbial gas tank should be filled back up.

It will be needed against a Red Bulls team that employs a high-pressure defense and fast attack. The Union did very well in combatting that in a scoreless draw at Red Bull Arena on May 26, and know they're in for a similar test this weekend.

"They have a true style," Curtin said. "We sometimes bring the best out of each other. As crazy as it sounds, the 0-0 game in the last one was still, I think, played at tempo that was really high, and was good soccer to watch."

The Red Bulls come in on a nine-game unbeaten streak, including two 4-0 routs of rival New York City FC: one in the league and one in the Open Cup's last round. But they're on short rest after Wednesday's 2-1 home win over the Seattle Sounders.

Expect a full-throttle game, though, as so often happens when these two teams get together. Their rivalry has plenty of spice, and the Open Cup has created much of it. This game will be the clubs' fifth all-time meeting in the tournament, and just the second at Talen Energy Stadium.

"We know what we're both about," Curtin said. "I think we both respect each other as clubs, but there is a rivalry there, between the fan bases, the coaching staffs."

If the Union win, they'll host either D.C. United or Orlando City — whose coach, Jason Kreis, was fired on Friday — in the quarterfinals.

Curtin has his full complement of regular starters available Saturday night, including Haris Medunjanin. The Bosnian midfielder is suspended for the Union's next MLS game, June 23 against the Vancouver Whitecaps, but the suspension doesn't carry over to the Open Cup.

It might, however, be extended for more MLS games — and frankly, the odds are high that it will be. Medunjanin got up in referee Sorin Stoica's face after being ejected, and could face an extra suspension for referee abuse.

"We have an idea of what the suspension is going to look like," Curtin said. He added that the exact length is still "a little bit up in the air" because the MLS Players' Association is involved with the matter.

Union vs. New York Red Bulls

U.S. Open Cup round of 16

Saturday, 7 p.m. at Talen Energy Stadium

Live video: Streaming at ussoccer.com

Overall series history: Red Bulls 14 wins, Union 8 wins, 5 ties
At Talen Energy Stadium: Union 6 wins, Red Bulls 5 wins, 2 ties

U.S. Open Cup history: Union 2 wins, Red Bulls 2 wins
At Talen Energy Stadium: Union 1 win, Red Bulls 0 wins

New York players to watch

M Tyler Adams: As his stock continues to rise, so do the odds that he leaves MLS for Red Bull Salzburg at some point this year. The most recent report said it will happen at the end of the season.

M Sean Davis: The 25-year-old central midfielder is a prime candidate to take over Adams' leadership mantle.

D Tim Parker: He impressed on the U.S. national team's recent European tour, especially the gritty 1-1 draw against France.