Olympiakos’s Nery Castillo, the attacking midfielder currently making international impact at the Copa America tournament in Venezuela, is fighting against time to regain full fitness for Mexico’s semifinal against Argentina late tonight. Castillo, the tournament’s second top scorer with four goals, emerged with a swollen knee from Mexico’s 6-0 annihilation of Paraguay in the quarterfinals. «It’s worrying, because there are only a few hours before the game and if Nery can’t play, we will lose an important player who worries opponents,» said Mexico coach Hugo Sanchez. «There are players who can replace him and who have different characteristics,» added Sanchez. The 23-year-old Castillo, whose scoring spree at this summer’s Copa America has generated interest in the international transfer market, said, «I hope that time passes slowly so that I can play in the game, enjoy it and win it.» Recent reports named Valencia as one of the clubs interested in acquiring the Olympiakos player, who remains legally bound to the Piraeus team. The Spanish team, reports have stated, is willing to offer 15 million euros for Castillo. But there has been no official confirmation about this interest from the club. Another top-flight club, Chelsea, is also apparently contemplating making an offer to Olympiakos for the player. Reports have slated the English Premiership club’s price tag at about 10 million euros. Castillo, who made his international debut with Mexico early last month, scored his first of four Copa America goals against Brazil to help steer Mexico to a 2-0 win. He scored again against Ecuador, a game which Mexico won 2-1, before adding two more in Mexico’s 6-0 thrashing of Paraguay in the quarterfinals. The Mexican international went into the ongoing Copa America tournament having scored 12 goals in 25 games with Greek league champions Olympiakos last season. In terms of scoring, it was Castillo’s best season to date at Olympiakos. His previous best tally was seven goals in the 2003-04 season. Overall, the attacking midfielder has scored 30 goals with Olympiakos in 105 appearances.