"A lot of players might be tired, but I feel nice and sharp"

In this quote, Robbie Keane is revealing his current physical state in comparison to other players. He acknowledges that numerous players may be feeling tired due to the needs of the game, however he personally feels "nice and sharp." This suggests that Keane is confident in his physical abilities and is not experiencing any tiredness or exhaustion. He may also be suggesting that his sharpness provides him a benefit over other players who might be feeling tired. In general, Keane's statement shows his positive state of mind and preparedness to carry out at his best on the field.