Gary Johnson says his strikers must do considerably better if Bristol City are to halt their downward spiral.

A return of two wins in 17 games has seen the Robins drop out of immediate play-off contention in the Coca-Cola Championship and exit the FA Cup.

And manager Johnson today highlighted a continuing lack of goals as the biggest single contributory factor in his team's fall from grace.

City have scored just once in their last five outings and again fired blanks when losing 2-0 to Watford at Vicarage Road on Tuesday – despite starting the game with three forwards. Johnson fielded David Clarkson and Alvaro Saborio alongside big Patrick Agyemang, yet City's frontline struggled to create a single worthwhile goal-scoring opportunity against the Hornets.

Given the injuries and illness which have laid low top scorer Nicky Maynard and fellow attackers Jamal Campbell-Ryce and Danny Haynes, the manager faces a giant-sized headache as he bids to instil a cutting edge ahead of tomorrow's difficult assignment against Sheffield United at Bramall Lane.

Johnson accepted personal responsibility for defeat in Hertfordshire and admitted his tactics in the first half had backfired. But he also questioned the contribution made by his strikers and warned: "We need to be much, much better up front.

"Who knows what the score would have been had I decided not to change the team around? What I do know, though, is that we have to produce more quality going forward.

"We need someone to stand up and be counted. In fact, we need two people to stand up and be counted and put their names down for our striker roles.

"I'm being honest and our strikers need to do more. Watford's two forwards moved our defenders about, looked strong and caused us problems, but our strikers didn't do that and that was the crucial difference between the two teams.

"I need them to work harder, show more commitment and be that little bit cleverer in and around the penalty area."

While acknowledging the spirit which underpinned a vastly-improved second-half display in midweek, Johnson admitted: "We still have a lot of work to do, because we are not showing enough quality for long enough in games.

"We're only playing in fits and starts and it's up to me and my staff to find some way to draw a performance out of these players.

"Unfortunately, confidence is part of the problem and the players are beginning to believe the media reports which say we are not potent enough at this moment in time.

"But that is not the only reason we are not posing a constant threat going forward and the strikers have to take some responsibility.

"When a centre-half dominates a game like Martin Taylor dominated for Watford, something is not right. It's my job to find out what is wrong and to put it right."

Johnson will have learned a good deal from his team's below-par first-half display at Vicarage Road, but injury and illness mean he has few options as he plots an upturn in fortunes against Sheffield United.

Top-scorer Maynard and Haynes are unlikely to feature, while Costa Rica international Saborio failed to make an impact against Watford and was withdrawn at half-time.

Johnson hoped Agyemang, signed on loan from QPR last month, would provide a solution to City's lack of potency, but the big striker has yet to settle and looks as though he badly needs a goal to restore confidence.

Yet Johnson may be forced to play the former Ghana international alongside Clarkson tomorrow.

"These injuries are soul-destroying," conceded the Londoner, who has also been forced to make do without new signing Campbell-Ryce (calf strain) in the last two games.

"I think I know where the problem lies, but I don't have that many options at the moment."