US prodigy Freddy Adu arrived on Monday in Portugal to negotiate personal terms on a move to Benfica from Major League Soccer (MLS).
The MLS and Benfica have already agreed on a 1.5 million euros (US$2 million) transfer fee for the 18-year-old attacking midfielder, who was captain of the US team at the under-20 World Cup earlier this year.
Adu was to hold talks with Benfica officials and undergo a medical test, the club said in a statement. It did not provide further details.
Adu, who currently plays for Real Salt Lake, has wanted to play in Europe for a long time.
He has been one of the biggest stars of the MLS since he signed with DC United in November 2003 at age 14, becoming the youngest player in the competition's history.
Adu, now 18, was twice named an MLS All-Star - in 2004 and last year - and helped DC United capture the 2004 MLS Cup during his rookie season.
Real Salt Lake signed Adu from DC United last year knowing that when he turned 18 last month he would become eligible under FIFA rules to move to a foreign club.
Benfica have traditionally been one of Europe's stronger clubs, but it has not been able to match the spending of teams in wealthier European leagues such as England, Italy and Spain.
Benfica finished third in the Portuguese league last season behind FC Porto and Sporting Lisbon.
Benfica are also due to sign Argentina duo Angel Di Maria and Andres Diaz.