Sacramento Republic FC can make a strong claim to be the best team in its league through the first five weeks of the season.

And with a U.S. Open Cup bout against the Colorado Rapids of the MLS on Tuesday at Heart Health Park, the Republic will have another opportunity to prove it can compete with any professional side in the country.

Tuesday’s match will be the biggest of the young season for manager Mark Briggs’ club, which naturally meant it was time for an annual pizza party following their training session Friday.

“This is the stuff that people don’t see and the stuff that people don’t realize has such an impact,” Briggs said, holding a customized pizza fresh out of a portable oven stationed just outside the team’s weight room at Cosumnes River College. His players were lined up behind him making pizzas of their own with the help of staffers along an ingredient assembly line.

“But the more these guys are together, the more they have fun away from the field and enjoy one another, the more they rely on one another on the field,” Briggs said. “I think that shows that our group last year, we were really close, and this year they’re really close. It’s important and it’s what you need in order to have success.”

Camaraderie has been an early-season theme for Republic FC amid the strong start to the club’s campaign. They sit in first place in the Western Conference at 5-0-3 and remain the USL’s only unbeaten team through eight games. They have an impressive plus-12 goal differential, six more than Charleston Battery, who have the second-best differential at plus-six.

The Republic came into the season with the expectation to compete for a USL Championship with the addition of top goal scorer Russell Cicerone to their top line. They beat three MLS sides during their run to last season’s Open Cup final, and are hoping that experience can help them advance to the Round of 16 with a victory over Colorado.

“I feel like in every phase of the game, we’re comfortable,” Briggs said. “Whether we’d be defending and handling pressure, whether it be in possession of the ball in our own half or in possession in the attacking half, or we’re pressing, I feel like in every phase we’re comfortable and the guys have a better understanding of one another.”

The Rapids are 10th in the MLS Western Conference standings but haven’t lost a match since March 18. They’ve gone 3-0-5 since that defeat to Minnesota United, including a 3-1 victory in their last Open Cup match against the Northern Colorado Hailstorm of USL League One.

Colorado is expected to play the bulk of its A-side Tuesday against Sacramento while many teams use the Open Cup to get experience for their bench players. Colorado’s payroll last season was roughly $11.6 million. The Rapids this season are expected to have a payroll 12 times higher than Republic FC.

“I know a lot of USL teams, including ourselves, cherish the opportunity to play against an MLS team,” defender Conor Donovan said.

Last year, of course, Republic FC beat three MLS teams — the San Jose Earthquakes, L.A. Galaxy and Sporting Kansas City — to reach the Open Cup final against Orlando City S.C.

“I think it gives us the confidence we can compete with anybody,” Donovan said. “Obviously, the games we played in last year were special and they were hard, so we know what it takes and how hard it can be. So that’s exactly what we’re preparing for with Colorado. We know it’s going to be a grind and a really hard game.”

Added Briggs on the Rapids: “They have a fantastic group. I think first and foremost, we have to be prepared for the caliber of player they have. They have players that can hurt you in any moment, and players who don’t miss chances, and that’s why they’re at the level they’re at. When they have an opportunity, they usually finish the opportunity.”

Republic FC will be without one of its key figures for the foreseeable future due to injury.

Midfielder Rodrigo Lopez last week had surgery to repair the rectus tendon in his right quadriceps. The procedure was performed by Dr. Brian Haus, a sports medicine specialist at UC Davis Health. The team said an update on Lopez’s time frame for return will be provided in the coming weeks once he’s able to begin his rehab.