Chelsea manager Jose Mourinho has admitted that his side need a striker with a "killer instinct", having watched them fail to break down a stubborn Norwich City defence yesterday.

The Blues saw their Premier League title hopes all but ended courtesy of the goalless draw at Stamford Bridge as Chelsea once again struggled to find a way past a team at the wrong end of the table.

Mourinho has been heavily linked with a summer move for Atletico Madrid striker Diego Costa, and the Portuguese manager acknowledged that his side were missing the type of player who could unlock determined defences.

"Against the teams that are more defensive, more aggressive, more worried about trying to keep a clean sheet than really to play, we keep saying the same. We have good players, but we don't have the kind of striker able to, in a short space, to make an action, to score a goal, to open the gate," Mourinho told Chelsea TV.

"In these kind of matches you just need to open the gate. When you open the gate, the gate is open and you go on to win much more. We weren't able to do that. We have to try to win as a team, to improve as a team, but also add the attacking player with that killer instinct and the number of goals that push teams to different levels.

"It's something our club is going to try, respecting obviously that we have good strikers."

Chelsea are now one point behind Manchester City and Liverpool in the Premier League title race having played a game more than both of their rivals.