Tyler Heaps sat on his couch over the weekend, and it finally hit him.

“Holy cow,” he said, “this is really happening.”

Heaps is the sporting director and general manager of San Diego FC, the Major League Soccer expansion franchise that holds its first training session next Monday, plays its first closed-door exhibition game Jan. 25, has its season opener Feb. 23 in Carson against the defending champion Los Angeles Galaxy and takes the field for the first time at Snapdragon Stadium on March 1 against St. Louis City.

“It’s been a whirlwind, because I went from the highest of highs to the lowest of lows,” said Heaps, who married to U.S. Women’s National Team star Lindsey Horan on Dec. 28 in Colorado Springs, Colo. “You’re with all your family and friends for 48 hours, you throw this massive party, and then you’re saying goodbye to your wife in an airport. Like, how depressing is that?

“Then I get back and my body was completely shutting down. And then this weekend, I’m thinking that in five or six days we’re going to have a full team of players here, in a new facility, in an amazing part of the world, a brand, new team from scratch. I think it was the first time I really got excited. … It’s been a long road.”

MLS rosters have 26 players. San Diego FC is up to 20 and could add a few more pieces — key pieces — before players report for training camp on Friday. The first team meeting is Saturday morning. Coach Mikey Varas holds his first practice Monday morning.

The latest addition to the roster is 30-year-old winger Emmanuel Boateng, a veteran of four MLS clubs who is from Ghana and is a product of the Right to Dream Academy there. He is known for bringing energy off the bench, along with a familiarity of the RTD system that will be installed across SDFC’s youth development system at the $150 million complex near completion on Sycuan tribe land in East County.

The biggest holes in the roster are at right wing and central midfield, but those could be plugged shortly.

SDFC pursued Chula Vista native Paul Arriola, a natural right winger with national team experience who was left unprotected by FC Dallas in the MLS Expansion Draft. But they couldn’t come to terms on a contract extension, and SDFC opted to look elsewhere.

That appears to be Oleksandr Zubkov, a 28-year-old right winger from Ukrainian club Shakhtar Donetsk who has five goals and five assists in 12 games this season. He would be the club’s second designated player (which doesn’t count against the MLS salary cap) and operate on the wing opposite the other DP, Mexico’s Hirving “Chucky” Lozano.

Both are modern, inverted, technical wingers, meaning they prefer to cut inside to their dominant foot and put pressure on center backs instead of merely bombing down the sideline and whipping in crosses. Zubkov is left-footed and plays on the right side; Lozano is right-footed and plays on the left.

But first, the two clubs must agree on a transfer fee. Soccer journalist Tom Bogert reported that SDFC offered $5 million but Shakhtar Donetsk wants more. The Transfermarkt website values Zubkov at $8.3 million.

Heaps said they’re close to signing a playmaking central midfielder, also from the international market.

That would still leave two more central midfield spots to fill.

“We need a few key bodies there,” Heaps said. “It’s about trying to find the right balance. We’re trying to find different types of profiles, guys who can play between the lines, guys who can go win the ball back for us, guys who can play low in build versus high in build. We just have to get the construction of it right.”

Varas and Heaps are proponents of a 4-3-3 base formation, but that is mostly for its fluidity and flexibility, allowing a variety of tactical options when defending or building the attack.

“What our roster shows, and hopefully it shows when it gets on the grass and not just on a whiteboard, is that we have different types of profiles,” Heaps said. “We can still play quite a few different ways. That’s why the midfield makeup is so important. We can build with a double pivot, we can build with a single pivot, we can have double 8s, we can play with a single 10.

“For us, it’s about giving Mikey different options and then having construction based on the upcoming opponent.”

Here’s a position-by-position look at the roster so far.

Goalkeepers: CJ dos Santos, Pablo Sisniega, Jacob Jackson.

Defenders: Paddy McNair, Andres Reyes, Christopher McVey, Jasper Loffelsend, Franco Negri, Hamady Diop, Ian Pilcher.

Midfielders: Jeppe Tverskov, Heine Gikling Bruseth, Anibal Godoy, Manu Duah.

Forwards: Lozano, Boateng, Marcus Ingvartsen, Tomas Angel, Alex Mighten, Anisse Saidi.

(Not included is 18-year-old goalkeeper Duran Ferree, whose loan to Danish sister club FC Nordsjaelland has been extended. Pilcher, a first-round pick from Charlotte in the college SuperDraft, has not yet signed but is expected in camp. The club has not yet announced Negri, but the Argentinian left back was released by Inter Miami and there are multiple reports that SDFC acquired him via the MLS Re-Entry Draft.)