Liverpool are in danger of losing influential skipper Steven Gerrard for the first leg of the UEFA Champions League semi-finals versus Chelsea on Tuesday. Gerrard is struggling with a neck injury, which forced him out of the Reds' 2-0 Premiership win at Fulham on Saturday. "We don't know at the moment," Liverpool coach Rafa Benitez replied when asked about Gerrard's availability for the game. "Steven is working with the physios. He is improving but it is still too soon. You always have to be careful with the neck." However, Benitez was positive that Sami Hyypia and Javier Mascherano will be fit to face Chelsea after the duo suffered knocks at Craven Cottage. "I think Hyypia will be ok. He felt a little bit dizzy after a knock to the head but I think it's ok now," said the Spaniard. "Mascherano had three knocks but I think he too is ok."