Jose Mourinho believes Chelsea's incoming 'killer' striker will open the floodgates after another missed opportunity put paid to the Blues' Premier League title hopes.

Mourinho has long lamented his toiling strikers' troubles in front of goal and indicated his desire to land a prolific goalscorer next term, with Atletico Madrid's Diego Costa reportedly the number one target and the possibility of Fernando Torres returning to his former club in part-exchange.

As well as helping Chelsea match their formidable record against the Premier League's elite, the new forward will be expected to rough up also-rans like Norwich, whose 0-0 draw at Stamford Bridge on Sunday saw the Blues concede further ground to Manchester City and Liverpool.

"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," Mourinho told Chelsea TV.

"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.

"In these kind of matches you just need to open the gate. When you open the gate, the gate is open and you go (and) win (by) 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 (to do), respecting obviously that we have good strikers."

The futures of captain John Terry, England left-back Ashley Cole and record goalscorer Frank Lampard - all out of contract imminently - are still to be clarified after the final home match of the campaign, which concludes at Cardiff next Sunday.

The Blues beat Manchester City twice, Liverpool twice, took four points from matches against each of Arsenal, Everton, Tottenham and Manchester United, but recent defeats to Aston Villa, Crystal Palace, Sunderland and the draw with Norwich have proved costly.

"It's much more difficult to get results against the big teams," Mourinho added.

"Mentally you have to be stronger, by the strategic point of view you have to be stronger too.

"When we have that amazing record against the top teams, I think it's a fantastic achievement and a good base to start next season."

Chelsea's home record reads played 19, won 15, drawn three and lost one, the controversial defeat to Sunderland which saw Mourinho relinquish his 77-match unbeaten league record at home.

"If you forget the Sunderland festival, because for me it was not a football game, it was a festival, the (home) record was good," Mourinho said.

"We lost six points at home, with three draws, which is still a good record.

"The matches with the top teams the record is really amazing, difficult to repeat next season even if, like we expect, we are stronger."

Norwich midfielder Jonny Howson knows their top-flight status can be ended if Sunderland beat West Brom on Wednesday night.

Even a draw for Sunderland, who are two points above Norwich, would all-but consign the Norfolk club to relegation as they have such an inferior goal difference that a win at home to Arsenal next Sunday would be immaterial.

"It's out of our hands now and hopefully we get a little bit of luck," Howson said.

"The ball's back in Sunderland's court. We need a little bit of luck from West Brom to take it to the last day of the season.

"Just two wins away all season. You're going to go nowhere with that kind of form.

"We're pleased with the performance, but it's frustrating: why couldn't we have done that more often?"