Is delap who plays for doncaster any relation to the delap who plays for sunderland in football?

No, the Delap who plays for Doncaster Rovers is not related to the Delap who plays for Sunderland. They are two different individuals with the same last name. The Delap at Doncaster is likely referring to a different player than the one at Sunderland, and there is no known familial connection between them.