Sheffield United: The performance was poor but its implications could be even worse

But with Billy Sharp, their captain and leading goalscorer, limping-off with a hamstring complaint after Chris Basham suffered exactly the same fate, the shadow of a dramatic but ultimately frustrating encounter against Millwall threatens to cast a shadow over the remainder of their campaign.

Although Chris Wilder acknowledged afterwards that United had yet to ascertain the exact level of damage the duo suffered before Jake Cooper's added-time equaliser cancelled-out Gary Madine's opener for the hosts, it seems unlikely either will be available for Good Friday's visit of Nottingham Forest. With John Egan already ruled-out of that match through suspension - the centre-half was dismissed during the closing stages for deliberate handball on the line - Wilder's squad faces the greatest test of its strength and depth at a critical moment in the race for automatic promotion.

"They're hamstring injuries and I don't know how serious they are," the United manager admitted during his post match interviews. "It's too early to know but we'll have a look at them and then see."

"Well, if you lose your captain and a good player that's a concern isn't it," he added, after being asked by a journalist if he was "worried" about the situation.

Although it was a witless question, given not only the circumstances but also the result, Wilder's acerbic response betrayed the potential implications of entering the meeting with Forest and next week's derby at Hull City without Basham and Sharp. Indeed, if grade two or three tears are diagnosed, they could even miss the play-offs if United fail to claw back the three points gap now separating them from second-placed Leeds.

Despite struggling to break down Millwall, something Wilder attributed to his team's mindset, United took the lead early in the second-half when Madine scored for the third time since arriving on loan from Cardiff City during the January transfer window.

When Ben Marshall missed from the spot after Egan had seen red for 'saving' Tom Elliott's goalbound header, they appeared destined to claim a hard-fought but vital win. However, with only seconds remaining, Cooper turned home from close range to salvage a draw for the Londoners.

Wilder, already frustrated by United's performance, ran onto the pitch at the final whistle to confront referee David Webb who had failed to punish a foul on David McGoldrick during the build-up to Millwall's leveller.

"It's uncharacteristic from my team," Wilder said. "It's uncharacteristic for me to run on and confront the referee at the end. 

"Ryan Leonard on David McGoldrick right in front of the referee, I trust my eyes. I trust them and I trust them even more after watching the film of it."

"You take what is given at this stage of the season, but for a referee to miss that, right in front of him, well. I'm not blaming the performance on him but on 94 minutes, I'm backing him to get that right," he added. "There's quite a bit to play for at this level of the Championship isn't there. 

"To get that decision, right in front of him, wrong is astonishing. I told him he hadn't got it right and he should have done. Everyone in the ground got up and jumped on it."