Jamaica’s Darren Mattocks, right, challenges Omar Gonzalez during the second half of the Gold Cup final in Santa Clara, Calif., on July 26. (Marcio Jose Sanchez/Associated Press)

D.C. United took advantage of MLS’s four-hour trade window Sunday, addressing issues in two positions by acquiring Jamaican forward Darren Mattocks from the Portland Timbers and French central defender Frederic Brillant from New York City FC.

United did not relinquish a player in either deal: It sent an international roster slot to Portland and $75,000 of general allocation money and an international slot to NYCFC. These were the first of several expected moves in the coming weeks for an organization that retained 16 of 28 players after finishing tied for last with the Los Angeles Galaxy in MLS’s overall standings.

“There’s still a lot of work to do,” General Manager Dave Kasper said. “We’ve done quite a bit of international travel [for scouting purposes]. We’ve talked to every team in the league about trade possibilities. The re-entry drafts are coming up soon and free agency. So there are multiple conversations going on.”

Mattocks, 27, is a Jamaican national team player with speed and an inconsistent scoring touch. He has recorded 24 goals in six MLS seasons but just eight in the past three years with Vancouver and Portland. United agreed to pick up the option on his contract, which was worth $300,000 in base salary in 2017 — a high figure in MLS for a reserve (24 appearances, 11 starts).

His impact on matches, however, caught United’s eye.

“We haven’t had this kind of speed in our team in a long time,” Kasper said. “He is explosive. He stretches the other team’s defense. He draws penalty kicks. He is such a threat getting behind defenses, but also his soccer is good.”

United officials have talked about targeting a proven goal scorer, perhaps from overseas, to fill a large frontline void. The club was tied for last in scoring this year (31 goals in 34 matches) and equaled its own league record for scoreless performances (17).

Is Mattocks the answer?

“We view him as a big piece,” Kasper said. “We will look to sign more attacking pieces. We’re not just looking for one guy; we’re looking for several guys who can bolster the attack. We feel he’s a good starting point for us as an offseason signing.”

Over the last three months of the season, Mattocks stepped into the lineup for injured striker Fanendo Adi and posted three goals and two assists, including the go-ahead goal against Vancouver in a finale that clinched first place in the Western Conference.

Mattocks, who starred at the University of Akron, was the second overall pick by Vancouver in the 2012 college draft.

He is ninth on Jamaica’s career scoring chart with 14 goals (in 39 appearances). Last summer, Mattocks scored against Curacao and El Salvador in the group stage of the CONCACAF Gold Cup. In the tournament final against the United States, he was in the starting lineup and came off in second-half stoppage time.

Mattocks, who has permanent residency and doesn’t count against the international roster limit, will bolster a frontline corps with only two returning players: Patrick Mullins and Bruno Miranda. Mullins scored five goals in an injury-marred season, all coming in two consecutive matches late in the campaign. Miranda, 19, arrived on loan from Universidad de Chile during the summer and, amid injuries, made five brief appearances.

Brillant (BREE-yawnt) was a full-time starter for NYCFC in 2016, lost his spot this year, then regained it when Maxime Chanot got injured. Brillant, 32, started the last 14 regular season matches and both playoff games.

NYCFC declined his contract option but extended a new offer, allowing the club to retain his rights. In making the trade, United negotiated a two-year contract with Brillant for a figure below his 2017 base salary of $280,000.

In the center back corps, he’ll join returning players Steve Birnbaum, Kofi Opare and Jalen Robinson. The club, however, sees Brillant as a starter.

“Certainly he has to come in and earn the job,” Kasper said, “but he’s been a starting center back on a very good team.”

Before signing with NYCFC, Brillant played five seasons in the Belgian league.

The trade window will re-open after Tuesday’s expansion draft, which will supply Los Angeles FC with five players. The re-entry draft will take place in two stages, this Friday and Dec. 21. United will have the No. 3 overall pick in the college draft, Jan. 19 in Philadelphia.

“Some things may get done before the holiday break, some may extend into January,” Kasper said. “We wanted to get these two deals done. Now we can sit back and evaluate. We still have resources to add more players. We think there are a lot of opportunities out there.”

Frederic Brillant (13) celebrates with New York City FC teammate David Villa in a 2016 MLS match against Vancouver. (Julie Jacobson/Associated Press)