About halfway between Tucson and Phoenix along Interstate 10 is Casa Grande, Ariz., a town just shy of 50,000 people.

Just big enough, in fact, to boast a Whataburger, an In-N-Out and a first-year Major League Soccer franchise's preseason training for about the next two weeks.

Minnesota United FC will set camp Monday in the isolated location, their first of three preseason stops in their quest to turn a still-growing 16-player roster into a full team.

After two weeks in Arizona, including two-a-day sessions and two friendlies (exhibition matches), the team will travel to Portland, Ore., for about a week, including a three-match tournament. Then it's off to Orlando for another week and two more matches before focusing on the March 3 regular-season opener on the road against the Portland Timbers.

But solidifying a team from an incomplete roster is no simple task — in not quite six weeks' time.

"It's hard work, preseason, and this will be my 40th," said coach Adrian Heath, chosen to lead the team just two months ago. "It's a lot of commitment, and you've got to get through it."

Heath, though, has the benefit of hindsight with an expansion franchise to guide him this time. As coach, he helped transition Orlando City SC from the United Soccer League to MLS in 2015. And he's remembered a few things he'd like to do differently now at United.

One of those aspects deals with finishing the roster. Heath said he isn't worried about having only 16 official players for a roster limit of 28. He said he believes 23 or 24 players would be enough.

"We've got some holes to fill, but I think the most important thing, and I've said this all along, is to get the right ones, not just to fill it," he said. "We probably rushed Orlando, probably one or two people too early, and regretted it."

Sporting Director Manny Lagos said United will have several younger players on trial as well as experienced players training with the team throughout the preseason, with possible signings stemming from those. Lagos also pointed to the USL as another possible source for players, though United will be one of two MLS teams without a USL affiliation with one specific team this season.

"We certainly will have USL relationships this year with several teams," Lagos said. "Meaning that we'll talk to them about loaning players or, frankly, taking players on loan from teams as well."

But with the players the team does for sure have, Heath said he will face a learning curve — being new to the club himself — trying to figure out how to motivate each individual. The main point the coach will strive to make to those without MLS experience, however, is the importance of building a strong foundation during the preseason.

"If you look at the record we had in Orlando [as a lower division team] against MLS teams, it was probably as good as anybody's," Heath said. "We got to the quarters or the semis of the Open Cup. We did well in every preseason game.

"But it's not the one-off. It's the Saturday-Wednesday, Saturday-Wednesday over a 10-month period that you have to maintain, and I think that's generally been the biggest stop up for a lot of the players, the level of competition over a really long period of time."

One player Heath won't have to explain this to is midfielder Collen Warner, United's fourth pick in the MLS expansion draft. The 28-year-old has played for four MLS teams and has established himself as a consistent starter. He was a part of Impact Montreal's first MLS season in 2012 and knows a preseason with an expansion team is more high stakes than usual, but that makes it all the more fun.

"There are basically 11 spots up for grabs," Warner said. "There's a little bit more of a dynamic to the preseason then as far as maybe just people coming back and trying to get fit and regain form. … For me, I think being in this situation is exciting, to be with what I see is a good group of guys who want to put their best foot forward when they go into the league.

"Because it is a really special experience to be a part of a team's inaugural year in MLS."