Jobs on the railways "will need to change to become more passenger-centric", according to the group that represents train operators.
The Rail Delivery Group (RDG) was responding to reports that hundreds of rail ticket offices could potentially close as part of a plan to modernise the railways.
RDG said it is talking to unions about how to address job changes.
One union said it will ballot staff if compulsory redundancies are used.
A spokesperson for the RDG, which represents the rail industry, said: "The pandemic has been an unprecedented financial shock to the railway.
"While no decisions have been taken over ticket offices, with the acceleration of changing travel patterns and more passengers migrating to digital technology, many jobs will need to change to become more passenger-centric.
"Train companies are working with unions on how to address those changes, while making sure the industry takes no more than its fair share from the taxpayer," they added.
The bosses of rail operators are in talks with the government about the closures, which may result in redundancies if staff cannot be moved into other roles, the Sunday Times reported.
During the pandemic, train passenger numbers collapsed and so did revenues.
Passengers numbers are still recovering, with big changes such as hybrid working affecting commuter levels and season ticket sales.
To ensure the railways kept running during the pandemic, the government stepped in to finance the industry.
Recently, rail minister Wendy Morton told the BBC that taxpayers had supported the railways with more than £14bn of funding, and that taxpayers had to get a good return on what they had invested.
As part of plans to modernise the railways, Transport Secretary Grant Shapps committed to modernising ticketing with more digitisation, as part of the Williams-Shapps plan for rail.
Manuel Cortes, TSSA general secretary, said: "Grant Shapps needs to realise that this daft plan is likely to result in the threat of compulsory redundancies, and if that happens we will be issuing ballots for industrial action.
"Closing ticket offices will not only be opposed by the unions but the public at large.
"Shapps must stand up to the faceless accountants in the Treasury because a properly run and fully functioning railway is vital in building an economic recovery from Covid.
"The government should share their plans in detail with us and commuters now if they are so sure that closing ticket offices and taking £2bn a year out of our railways is the best way forward.
"I'd strongly urge them to reconsider," Mr Cortes added.
Railway ticket offices are run by train operating companies in different stations, and not by Network Rail.