The ties between the Sacramento Republic and the San Jose Earthquakes are deep and complex. Quakes forwards Mike Fucito and Adam Jahn and midfielders Tommy Thompson and JJ Koval have all had stints at Sacramento as the two teams have begun to form what looks like a strategic bond.

Fucito and Republic FC forward Justin Braun played together at Montreal Impact and Chris Wondolowski, and Sacramento midfielder Octavio Guzman and goalkeeper Dominik Jakubek all played in college at Chico State. Republic FC forward Cameron Iwasa spent time with the Quakes as a trialist before the 2015 season. For San Jose midfielder Tommy Thompson, it’s a match against his home team and Jahn’s sister works in the Sacramento front office.

But bar all the old ties, it’s the simple fact that no other professional club exists within three-hundred miles, leaving the two alone to develop their local rivalry. Partly for that reason, they’re meeting in the fourth round of the US Open Cup — the oldest and only cup competition in the US — for the second year running.

Last year, the Quakes edged a tight 2-1 win over the MLS-hopefuls at Kezar Stadium in San Francisco. Tomorrow’s match will be the only game at Avaya Stadium this season where the traveling team will bring the majority of their fanbase, so a rollicking atmosphere, even on a Tuesday night, is due.

“Every game we play against them is heated, intense,” Jahn told MLSSoccer.com of the matchup. “Both teams want to win. They want bragging rights. So I think that’s the start of a rivalry.”

Despite the wide competitive gap — Sacramento won their inaugural 2014 season in the USL Pro, widely considered the third division of US soccer — Sacramento proved their worth in a tight, spiky 1-0 pre-season loss to the Quakes. The match became infamous after a section of the Earthquakes’ fanbase voluntarily left Bonney Field at the request of club officials after singing explicit chants. They may be cousins off the field, but it’s a battle once the match kicks off.

Yet the Quakes’ squad has been stretched thin and Dominic Kinnear faces a key MLS matchup with Seattle Sounders at the weekend to juggle. Innocent Emeghara is obviously still out long-term with a knee injury and wingers Cordell Cato and Sanna Nyassi are also away on international duty. The Quakes may also lose Chris Wondolowski to the US National Team’s Gold Cup squad.

Thus, Jahn, who has become a starter in the Quakes’ lineup following a loan spell with Sacramento last season, is likely to feature against his old side. Fucito, who scored Sacramento’s only goal in their meeting last season, may well be in the opposite dressing room earning his first Earthquakes start since March 2013. Holding midfielder Fatai Alashe started in a 0-0 draw with FC Dallas at the weekend following a month away at the Toulon tournament with the US Under-23 side and is likely to be rested as well. In his place Khari Stephenson or Jean-Baptiste Pierazzi may step in. Although the Quakes have consistently performed throughout the season, especially compared to their last-place finish in the Western Conference last season, they’ll hardly be fielding their strongest side tomorrow.

Sacramento, meanwhile, sit third in the twelve-team USL Western Conference, their potent offense scoring twenty-three goals in fourteen games so far this season. Former MLS midfielder Rodrigo Lopez has scored seven goals, the third highest tally in the USL. Although they won their last match 2-1 against Arizona United, they’ve won just two of their last five matches — including a thrilling 7-3 victory over Chula Vista FC in the Open Cup.

Nonetheless, they boast high hopes of expansion to MLS. When MLS Deputy Commissioner Mark Abbott visited Avaya Stadium for the announcement of the 2016 MLS-All Star game a few weeks back, he spoke to Football Every Day and other reporters on the topic. “What we’ve said is that over the next six months we’re going to evaluate a plan for when we would expand beyond twenty-four clubs,” he said. “When we announced that Minnesota would be joining the league we said at that time we would evaluate expansion beyond that.”

“Clearly, Sacramento would be a candidate for rounds of expansion in the future. The mayor, (and Sacramento owners) Kevin Negle and Warren Smith have done a fantastic job in that market and there’s a lot of enthusiasm. I visited last September but we haven’t yet made the plans for future rounds of expansion so I can’t speculate about it other than to say it’s impressive what is going on there and the commitment we’ve seen to the USL and Major League Soccer.”

Regarding a potential San Fransisco MLS franchise, he was considerably less positive. “There’s no active effort on San Fransisco now so that would be pure speculation at this point,” he said.

“What I would say as a general matter, and we saw that as a general matter a few weeks ago, when NYCFC played the Red Bulls in the first of the derbies there: rivalries are amazing. And you have them here with the rivalry between San Jose and Los Angeles (Galaxy). It’s tremendous and some of the great games in the league have been played between those two clubs.” It’s one of those rivalries that will be on display tomorrow night at Avaya Stadium.