Jose Mourinho says the addition of a "killer" striker will be the key to Chelsea beating stubborn opposition next season.
Chelsea's Premier League title hopes were all but ended by a 0-0 draw with relegation-threatened Norwich.
They also lost recently against Aston Villa, Crystal Palace and Sunderland.
"We don't have the kind of striker able to, in a short space, make an action, score a goal, open the gate," Mourinho said.
"Against 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.
"In these kind of matches, you just need to open the gate. When you open the gate, the gate is open and you win much more. We weren't able to do that.
