United received financial considerations, known as general allocation money, from the Vancouver Whitecaps for Espindola, 31, and sent both general and targeted allocation money, as well as an international roster slot, to New York City FC for Mullins, 24.
Mullins was slated to arrive in time for Thursday’s session before a likely assignment Saturday at Toronto.
“Time will tell if it’s a good move, but I believe in the kid and I think his better years are to come,” United Coach Ben Olsen said. “And he has the ability to score goals.”
United (5-7-7) ranks second to last in the 20-team league in goals with 18. It has been blanked eight times and held to one goal seven other times.
Mullins, a Louisiana native, joins his third team in three seasons: He was selected by the New England Revolution in the first round of the 2014 MLS draft and enjoyed a four-goal rookie campaign but was left unprotected in the expansion draft.
Last year, despite starting just 11 league matches for NYCFC, he notched six goals and four assists. This year, with Spanish star David Villa (13 goals) enjoying an MVP season and the Bronx-based club atop the Eastern Conference, Mullins made only seven appearances (two starts) totaling just 230 minutes, recording no goals and one assist.
Between mid-April and early July, Mullins appeared in one league match. Last Sunday, he entered in the 88th minute of a 3-1 victory at Montreal.
United is quite familiar with him: The technical staff watched him regularly in College Park over a four-year career; he trained informally with United during Maryland’s offseason; and D.C. considered drafting him before deciding on center back Steve Birnbaum with the No. 2 pick. (Mullins slid to No. 11.)
He finished his Maryland tenure second on the program’s all-time leaderboard in both goals (47) and points (119). As a junior and senior, Mullins won the Hermann Trophy as the nation’s best player – the first repeat men’s winner in 17 years.
Over 2½ seasons, Espindola recorded 20 goals and 17 assists in 59 league matches. In his first year in Washington, he played a key role in United rising from the worst record in MLS history in 2013 to first place in the Eastern Conference in 2014. His 11 goals and nine assists earned him team MVP honors.
A fiery and competitive figure, Espindola, at times, struggled to temper his emotions. In the 2014 playoffs, he accosted an assistant referee and was subsequently suspended for the first six matches the following year. He finished with five goals and seven assists as United returned to postseason.
This year, he had started 10 of 19 matches and was tied for the team lead in goals with four, including a late equalizer as a substitute at Columbus on Saturday.
“Fabi and I have been through a lot in the last 2 ½ years,” Olsen said. “Overall, it’s been a great relationship and he has really helped this club out. He plays with passion and been a big part of the resurgence of this team. We’re sad to see him go, but we saw an opportunity to pick up a younger asset.”
Part of United’s motivation to move Espindola was financial. He was United’s lone designated player, a classification that allows teams to sign high-priced players outside normal salary cap guidelines. The trade cleared an estimated $250,000 in cap space.
Although the MLS players’ union says he is earning $200,000 this year, middling by league standards, Espindola makes considerably more. The designated player threshold is $457,500. An exact figure was not available and the reason for the discrepancy has never been explained.
Mullins earns $96,250 in base salary and $126,250 overall.
Espindola’s contract expires after this season, his 10th in MLS, and the club was not planning to re-sign him at or near his current salary.
Positional factors also played into the trade. In Olsen’s new formation with a deep-lying defensive midfielder, two pure wings, two central midfielders and a solo forward, Espindola did not have a natural place. He is best drifting in the attack, ducking under the front line and roaming into space.
Lloyd Sam, acquired from the New York Red Bulls two weeks ago, is the first-choice right wing. Patrick Nyarko, who last week returned from a concussion, and Lamar Neagle are comfortable on the left. Marcelo Sarvas, Nick DeLeon, Jared Jeffrey and Luciano Acosta are the central options.
Mullins, Alvaro Saborio and Alhaji Kamara are the primary front-line candidates. Mullins can also play left wing.
If United is seeking help from abroad, the transfer window is open until Aug. 3. The trade deadline is the same day. Teams are allowed to sign free agents until the MLS roster freeze Sept. 15.