He and his players now need to adapt with the centre-forward struggling to play again this season.
Bamford ruptured his plantar fascia - a ligament at the bottom of the foot - during the dramatic victory at Wolverhampton Wanderers. It is an injury that usually keeps players out for a minimum of six weeks, and he did it with only nine left in the season.
Having played so little in the last six months, Bamford will have to be eased back and after consecutive victories over Norwich City and Wolves, Leeds will be hoping the final matches of the season are not that important.
Often the full value of footballers is not really understood until they are missing, and the Whites’ fight against relegation this season has highlighted how vital Bamford is to them.
Leeds do not have anyone else who does what Bamford does for them. Dan James can lead the press as well – probably even better – but does not have Bamford’s goalscorer’s instinct or ability to hold the ball up.
His Wales manager, former Sheffield United and Huddersfield Town defender Rob Page spelt it out at the weekend: “Dan is not an out-and-out striker.”
Yet for most of his short Leeds career, that is what the Hull-born winger has been asked to be.
Rodrigo is more of a maker than a taker of chances, Tyler Roberts is out for the season anyway and youngsters Joe Gelhardt and Sam Greenwood would also be better playing off someone able to take the hits.
It is a luxury Marsch does not have and if Bamford was a loss for Bielsa, he is arguably an even bigger one for his successor, given his more direct style of play.
Bielsa probably counts himself extremely unfortunate to have only had 22 minutes – and a goal – out of Bamford from injuring his ankle in mid-September to the coach’s sacking in late February.
To have torn his hamstring celebrating the last-minute equaliser he scored against Brentford was particularly galling.
Not all of it can be put down to misfortune, though.
For starters, had Bamford not slid on his knees in celebration, his hamstring might have held up, but Bielsa has to take the lion’s share of blame. Bamford’s fitness was mishandled on his watch.
“He has played with a plantar fascia injury for the last 12 months and despite treatment and a prolonged period of rehabilitation, the injury has progressed from a partial tear to a full rupture,” Leeds’s head of medicine and performance Rob Price revealed.
Bielsa’s full-throttle training sessions had plenty of advantages, but easing players back from injury was not one. Bamford injured a quad muscle in training returning from the hamstring strain, and his plantar fascia coming back from that, before this time doing it in a match.
Bielsa’s reluctance to sign anyone else who could be a targetman exacerbated the problem.
So the toolbox Marsch is working with is not ideal.
He is trying to play a direct style which sees players bunch together to feed off second balls. Where Bamford usually played in splendid isolation for Bielsa, Marsch often uses two centre-forwards and the Argentinian’s wingers are effectively inside-forwards under the American.
Of Marsch’s four matches, Leeds lost the two where Bamford was on the bench (unused at Leicester City), and won the two he started, although both were won with him substituted.
Even so, both times they arguably looked better when he was on, and would have had three more goals in those 68 minutes had his finishing not been so rusty.
That is because Marsch’s style puts more emphasis on a No 9 who can hold up or flick on long balls. Leeds’s winner at home to Norwich was a case in point, Gelhardt getting on the end of Illan Meslier’s punt, flicking it to Raphinha then getting on the end of the ball back in.
So many people at the time pointed to Gelhardt’s height: 5ft 7in – it is not a job he is built for.
As he showed that day, it does not mean he cannot do it. Les Ferdinand was only five centimetres taller but his prodigious leap made him outstanding in the air. There are not many Les Ferdinands, though.
For strikers like Gelhardt, Greenwood and Rodrigo, taught in the modern way where centre-forwards are happier dropping between the lines to do the elegant stuff than being up where noses get broken, it will be as much about a change of mindset.
Just four matches into a new style, it seems unrealistic to expect Marsch to change course now, so others will have to adapt their games to do more of the things Bamford does.
But in the summer, this season’s lessons will have to be learnt. If Leeds are to build their style of play around individuals – be it Bamford, or Kalvin Phillips, another fundamental to Bielsaball who has missed too many matches – they need more than one person who can do the job.