Robson could be ready to bid for the tricky winger next month, as he looks to get his underachieving side up the table.
"We've had him watched, and I think he is coming to the end of his contract, so there might be a possibility there," Robson told Sky Sports News.
He also stressed that he had not been in touch with Blackpool as of yet.
Gary Speed will join the Blades this week ahead of the New Year's day clash with Wolves.