As D.C. United accelerates efforts to acquire roster help from abroad, the club is working on a trade for Colorado Rapids midfielder Marcelo Sarvas, the Insider has learned.

A two-way central player, the Brazilian won two MLS Cup titles with the Los Angeles Galaxy before moving to Colorado last winter and starting 21 league matches. If a deal is consummated, United would likely relinquish unspecified allocation money.

Club officials did not want to comment on possible personnel moves.

Sarvas, 34, comes at a high price: Last season, he earned $360,000 in base salary and $425,000 overall. However, sources familiar with the talks say Colorado will keep a portion of his number on its books.

Before joining the Galaxy in 2012, he played in Brazil, Sweden, Poland and Costa Rica.

With the CONCACAF Champions League quarterfinals less than a month away, the club is in a race against time to fill a midfield void left by Perry Kitchen, who turned down new contract offers to pursue European opportunities (which have yet to pan out).

The club is also preparing to be without starter Davy Arnaud, an on-field leader who, multiple sources say, is struggling to return from a season-ending concussion suffered late last summer. He left training camp this week to see a specialist in Michigan and is weighing retirement. Because Arnaud has a guaranteed contract ($225,000), he would remain on United’s books. To clear the hit on the salary cap, United’s investors would have to buy out the contract, which, in this case, they are unlikely to do.

The other primary central midfielder is Markus Halsti, who, amid injury setbacks, fell short of expectations last season. The club is experimenting with right wing Nick DeLeon in an interior role. He started in central midfield in the preseason opener Friday against Sweden’s Elfsborg in Bradenton, Fla.

At the draft this month, United used a first-round pick on German central midfielder Julian Buescher (Syracuse), who could contribute as a rookie but will need time to adapt to the pro level.

Two defensive midfielders are on trial at training camp: Costa Rica’s Ariel Rodriguez (Alajuelense) and Trinidad and Tobago’s Kevan George (Columbus Crew).

On the higher end of candidates, General Manager Dave Kasper and managing general partner Jason Levien are in Italy exploring the possibility of acquiring AC Milan midfielder Antonio Nocerino. The Italian club is trying to get him off its books. The D.C. duo attended Milan training Friday and met with Nocerino, a 2012 Italian national team member at the European Championship who has spent the bulk of his club career with Palermo and AC Milan but gone on loan frequently.

Sources say United is willing to offer a two-year guaranteed deal worth between $600,000 and $800,000 per season, which would probably make him the club’s highest-paid player. Nocerino, who turns 31 in April, is reportedly agreeable to a move to MLS. While Nocerino’s skill set would undoubtedly bolster the attack, there are questions as to whether he has the wherewithal for the demands of MLS, which are more physical than technical. Also, Nocerino has appeared in just two of 21 league matches (one start) for Milan this season.

At least one member of United’s delegation is scheduled to attend AC Milan’s Serie A derby against Inter Milan on Sunday.

One source said United is unlikely to finalize a deal.

United has also shown interest in free agent attacker Georgios Samaras, a member of the Greek national team at two World Cups and two European Championships. At 6 feet 4, he would serve as a target forward and perhaps prompt the club to move Alvaro Saborio, who was acquired last summer from Real Salt Lake for Luis Silva.

Samaras, who turns 31 next month, played 2 1/2 years for Manchester City and 6 1/2 for Celtic (53 league goals) before brief stays with West Brom and Al-Hilal in Saudi Arabia.

After recovering from a back injury, Samaras trained with the second-tier New York Cosmos this winter.

Italy and Greece are among four European destinations on United’s mission. France and England are the others.

United’s efforts to acquire central midfielder Leonardo Gil on loan from Argentina’s Estudiantes have not panned out.