Passengers told only travel is essential on Shrewsbury to Birmingham route on Saturday
Train travellers are being advised not to use services between Shrewsbury and Birmingham on Saturday unless absolutely necessary.
With no West Midlands trains because of rail strikes the only trains on the line with be those operated by Transport for Wales.
However bosses say that with the 2022 Commonwealth Games underway in the city the route is expected to be incredibly busy.
With no trains running across the county on Wednesday many early morning ones cancelled on Thursday because trains and carriages were not in their correct departure point.
Services were scheduled as normal for Friday the train operators said.
Transport for Wales which is responsible for services across Shropshire said there could be problems on a number of routes on Saturday due to the impact of industrial action at other train operating companies.
A spokesperson said: "Transport for Wales is not involved in Saturday’s industrial action by members of the train driver’s union ASLEF, but some of its services are likely to be extremely busy as a result of the severely-reduced timetable put in place by other operators."
"Services between Shrewsbury and Birmingham, where the 2022 Commonwealth Games are taking place, will be particularly busy as West Midlands Railway are not operating on Saturday."
"Extra staff will be deployed at stations to provide customer services and all customers are strongly advised to check for the latest travel information on the TfW website, mobile app or social media channels before making their journey.
"We would advise people not to travel unless it is essential."
People travelling to the first day of the National Eisteddfod near Aberystwyth may also find their train journeys may not be running.
TrawsCymru bus services to Aberystwyth are expected to be operating as usual.
The advice for people travelling on Friday and Sunday was that trains were expected to be busier than usual because passengers were having to re-arrange their journeys from the strike days.
Members of ASLEF at seven train companies will strike on Saturday over pay, with more walkouts planned next month.
The Department of Transport has urged union representatives to return to the negotiating table.
Sharon Graham, general secretary of Unite, said: "Workers are in the midst of a cost-of-living crisis and companies such as Centrica and Shell are reporting huge profits.
"As those in big business and the Government call for wage restraint, profiteering drives inflation through the roof. Unite will continue to fight for decent pay rises for our members."
