Ahead of two critical matches in the final round of qualifying for the 2014 FIFA World Cup, Sporting Kansas City midfielder Graham Zusi and defender Matt Besler were announced Monday as part of the U.S. men’s national team’s 23-player camp roster.

Zusi and Besler joined coach Jurgen Klinsmann’s squad Sunday in Denver, where the U.S. men will play Costa Rica on Friday at Dick’s Sporting Goods Park.

It’s the only home match among the first four in the CONCACAF Hexagonal qualifying round for the U.S. men, who also play rival Mexico on March 26 at Mexico City’s Azteca Stadium.

“I get just as excited every time I get called up and, obviously, it’s an honor to be selected again,” said Zusi, who has been called into the U.S. men’s camp on eight occasions now. “It’s pretty much a must-win for us. We’re definitely going into Colorado needing those three points.”

Zusi, 26, appeared in last three World Cup qualifiers during the semifinal round last year – all wins – and subbed on Feb. 6 during a 2-1 loss at San Pedro Sula, Honduras, in the first match in the final round of CONCACAF qualifying.

Overall, he has made eight appearances for the U.S. men.

“Every time you’re with the guys, you become more comfortable with them and as much training as you can get helps,” said Zusi, who led MLS with 15 assists last season and was a finalist for league MVP. “These four or five training sessions before the game on Friday will be very helpful.”

Meanwhile, Besler, 26 – a native of Overland Park who became the first Kansan to start for the U.S. men when he got the nod during a friendly Jan. 29 against Canada in Houston – continues to adapt as well.

He was called into camp for the first time last August ahead of a friendly at Mexico and returned to the U.S. men’s camp for the second time in January.

Besler was held over for his third camp before the qualifier against Honduras, though he did not play in that match.

“I think I’m taking the right steps,” Besler said. “The Mexico call-up was almost to get my feet wet and to see what it’s like. The Honduras call-up was more of ‘I’m ready to play if they need me.’ Now, we’ll see when we get there about playing time and opportunities, but I feel like I’m definitely a part of this team and I’m ready to contribute.”

Unlike Sporting KC, 1-1-1, which has a marathon 34-match season to accrue points toward a playoff berth. There are only 10 games in the final round of World Cup qualifying and the U.S. men were the only team not to get a point in the first qualifying match.

“There’s pressure on the all the games, especially since we didn’t get a result in Honduras and this is our first home game,” Besler said. “Everyone says the formula is to win your home games and get a point on the road. We’re one point behind now since we lost, so the three points against Costa Rica is huge.”

Of course, Zusi said not much changes in terms of his mentality wearing the red, white and blue as opposed to Sporting blue.

“It’s a lot of the same mentality,” Zusi said. “The only difference is that you’re with a new group of guys and the games are – I don’t want to say more rides on those games, but the margin for error is a little slimmer.”

Neither Zusi nor Besler will be available Saturday when Sporting KC travels to play the New England Revolution, who will be without Honduran striker Jerry Bengston.