Marcelo Bielsa says Leeds United's 'injury crisis' will test the club's planning

The Leeds United head coach said the spate of absentees would examine “the work we did when we built this group” as he faced up to the setbacks which have weakened his hand ahead of a much-anticipated trip to London.

Leeds are taking an unbeaten league record to Millwall for the second time in two seasons and aiming to avoid the sobering defeat at the New Den which ended their promising start last September.

Bamford, the club’s recent £7m signing, was ruled out until after Christmas on Tuesday with a serious knee injury and Bielsa is effectively without a proven Championship centre-forward after a calf injury suffered in training ruled Roofe out of this weekend’s fixture.

Roofe won the division’s player-of-the-month award for August with four goals and two assists, steering Leeds to the top of the table, but will not make the journey south on Friday and is expected to be absent for at least a fortnight. Youngster Tyler Roberts is in line to replace him in what would be his league debut.

Millwall v Leeds United: Roofe and Hernandez join Bamford and Berardi on sidelinesHernandez, meanwhile, will be absent for up to five weeks with a hamstring strain sustained in a training session earlier this week. The Spaniard was bidding to return against Millwall having missed a 0-0 draw with Middlesbrough before the international break.

A knee problem is set to sideline Berardi until next month and Bielsa, who deliberately opted to construct a small squad in a summer which saw just six new signings, will be forced into key alterations as Leeds attempt to break their traditionally poor record at the New Den.

“I'm worried when I analyse the reality,” Bielsa said. “I do not ignore the reality but I’m always full of hope before a game. Before any game a lot of hope invades me. I have expectations for what I can get.

“I can't deny the fact that it’s difficult. We always talked about the fact that we had 18 starters and four players were in this group as youngsters. So now we will see how good the work was that we did when we built the group.

“I have the intention of giving an answer that isn't an excuse but I can't betray common sense. If I say we can solve the absence of Pablo, Bamford and Roofe, it would be ignoring what they represent for the team. But I have the conviction that we’ve been working with more than 11 players.

WATCH: Leeds United captain Liam Cooper speaks to the media ahead of Millwall trip“We have to accept the fact that we have to find solutions to the problems we are facing. When we talk about football we talk about comparisons and our opponents also have realities different to ours, and problems to face.

“We designed a group that has to be able to solve these kind of problems. Saturday's game is a good time to show how we worked regarding this.”

Roberts was a January signing from West Bromwich Albion but he suffered a shin injury within days of joining Leeds and took until last month to make his first competitive appearance.

The 19-year-old is yet to play in a Championship match but he made his international debut for Wales last week, replacing Gareth Bale as a second-half substitute in a Nations League win over the Republic of Ireland.

Bielsa’s other options are academy players Ryan Edmondson and Jack Clarke, neither of whom have played at senior level. Clarke caught the eye with an impressive display in an Under-23s win over Bristol City on Friday, the match in which Bamford was injured.

“The first option we have is Tyler Roberts and we have also other possibilities,” Bielsa said.

“He’s made many efforts in the last international games in the international games he has played as a number nine. It’s an option for us.”