Can Chelsea triumph again in Europe? Will the legs of an admittedly ageing team stand up to possible fatigue in Lisbon tonight. There were ominous signs on Saturday in the London derby at home to Spurs, the better team in a goalless draw, that certain key Chelsea players are waning. Didier Drogba looked a jaded figure against Tottenham, while Frank Lampard\'s fading in the second half seemed to suggest that the dismissed manager, Andre Villas Boas, may have been right to exclude him so often. Not that Benfica themselves, though top of the Portuguese league, looked sharp last Friday when held to a goalless draw by modest Olhanense, where their chief playmaker, the Argentine Pablo Aimar, was sent off — though he can play this evening. At least, the Chelsea defence, this time, doesn\'t have to face the electric South American menace of Cavani and Lavezzi, who gave them so much grief in Naples. Another Argentine, the swift and skilled right flanker Nicolas Gaitan, will doubtless keep Ashley Cole occupied, while at least Chelsea can call on three centre-backs: John Terry, back impressively now from his injury; Gary Cahill, running into form in recent games at the Bridge; and the quick, but impulsive David Luiz, for whom it is said Barcelona are ready to pay a colossal transfer fee. Such sums of money, however, mean little to the billionaire oligarch owner of Chelsea, Roman Abramovich, who can draw them metaphorically out of his back pocket. But it does seem highly significant that Barca, who tomorrow visit San Siro to face AC Milan, clearly feel that they need reinforcements in central defence, where Puyol, that resilient figure, is no longer young, while Pique has been somewhat out of sorts. Nonetheless, I don\'t think Luiz who, like Cahill, had a wretched game in Naples, would be my choice. He is talented beyond doubt, but he\'s also dangerously adventurous. At the San Siro, the Barca central defence must face Zlatan Ibrahimovic, who tore the Arsenal defence to shreds in the first leg of the previous round but did little of note — such is his pattern — at the Emirates. He could, however, be a major threat to Barca in this tie.