COMMERCE CITY — The Colorado Rapids held their first training session of the preseason at Dick’s Sporting Goods Park on Sunday, before heading this week to Tucson for the Desert Diamond Cup.

The Rapids opened camp in Boulder, then spent 10 days training in Los Angeles at the Rams facility, returning late last Wednesday.

“That was tremendous,” said Rapids sporting director Padraig Smith. “The Rams really pulled out all the shots for us. Good fields, good environment, good weather, which obviously helps.”

Colorado played two friendlies against Ventura County Fusion of the Premier Development League (PDL), drawing the first match 1-1 and winning the second 6-1.

The Rapids will open the Desert Diamond Cup on Wednesday with a match against Sporting Kansas City. They take on New England Revolution on Saturday, New York City FC on Feb. 22, and depending how the tournament shakes out, they’ll play a final game against MLS competition on Feb. 25.

“It’s more about seeing what we’ve been working on here and can we pull it off on the pitch,” Rapids striker Kevin Doyle said of the trip to Tucson. “Whether we win games or lose games, we want to get fitness from it, you want to feel personally that you got through 90 minutes at some stage and feel fit and strong. But just to see some of the moves and some of the shape and organization we’re working on that it translates onto the pitch.”

The Rapids open the season on March 4 at Dick’s Sporting Goods Park against New England.

Howard update. Goalkeeper Tim Howard continues to rehab from a groin injury that ended his 2016 season. He went to Memphis over the weekend to have the trainers from the Memphis Grizzles — with whom he did offseason rehab — re-evaluate his progress.

“As we get to Tucson, the next phase of his recovery is going to be a little bit more intense,” Rapids coach Pablo Mastroeni said. “Again, there’s no pressure on him to be ready for the first game of the season. Having said that he’s made some really good progress.”

Mastroeni said Howard has progressed to diving and passing the ball about 20 yards, which he’s felt good with.

“It’s all about gradual improvements and doing so at a level he feels comfortable with,” Mastroeni said.

Gashi’s Achilles. Rapids’ 2016 Golden Boot winner Shkelzen Gashi has been dealing with some inflammation in his Achillies, Mastroeni said Sunday. Gashi was jogging off to the side during the Rapids’ training session on the turf fields at DSG Park.

“We sat down and came up with a good two-and-a-half week plan where we can continue to build his fitness while not stressing the inflammation in his Achilles,” Mastroeni said.

Mastroeni said the Achilles issue was something Gashi dealt with last season and had weeks in which he sat out training sessions. The Rapids coach said the goal this preseason was to also strengthen Gashi’s Achilles so it doesn’t become an issue he’s dealing with for the next 10 months.

Serna stronger. Rapids midfielder Dillon Serna participated in some drills Sunday, but jogged off to the side when the Rapids’ training session increased in intensity. The homegrown midfielder looks as though he’s bulked up his upper body this offseason as he works to return from a season-ending knee injury.

“Serna’s done an exceptional job of not only recovering from the knee injury, but adding probably five or six pounds of muscle, strength and it showed in his preseason testing as well,” Mastroeni said. “He’s in a great way.”

Mastroeni said Serna likely won’t be cleared to join full training until after the Tucson trip.

Footnotes. The Rapids said midfielder Bismark “Nana” Adjei-Boateng’s P-1 visa paperwork has been approved and he arrived in Denver late Sunday night. He will travel with the club to Tucson. … Rapids trialist Jun Marques Davison left the club following the trip to Los Angeles. He has rejoined the Charlotte Independence. … Rapids fourth-round draft pick Peguy Ngatcha is no longer with the club. … The Rapids two homegrown signings Kortne Ford and Ricardo Perez, and three remaining unsigned draft picks Sam Hamilton, Liam Callahan and Jamie Siaj were in Florida over the weekend for an MLS rookie symposium. They’re expected to be with the team at the Desert Diamond Cup.