Engineering work is taking place between St Denys and Cosham, closing all lines early on Monday morning.
As a result, the 04:50 Fratton to Bristol Temple Meads service will start from Southampton Central at 05:33.
For Fratton, Cosham, Portchester and Fareham, you should instead travel by later services.
Check before you travel:
You can plan your journey using the National Rail Enquiries Journey Planner.