I see Rangers lone man up front being a straight choice between Cousin and Darcheville.
Darcheville is a much more bustling and powerful player, who will cause problems in the Barca defence, even though he is not fully fit, and is very unlikely to score. If he gets the ball then his duty is to hold it up until the midfield support arrives. The problem with this however, is that under Walter Smiths tactics, the midfield support stays on the halfway line.
Cousin is fitter, is still a powerful player in his own way, and has more of an eye for goal and the unexpected. If he gets the ball then he will be looking to take it all the way and stick it in the back of the net. However, can he get through the entire Barcelona team on his own? If Smith plays him, the he will send out a message(in my opinion) that he is actually looking to score goals.
Id go with Cousin personally.
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