Sir Alex Ferguson and his backroom team are determined to be as patient as possible with the injury, to give Rooney the best chance to be fit for next week's Champions League tie with Inter Milan.
But Rooney has stepped up his training schedule this week and the Manchester United manager admits he is in contention for a run-out, most likely as a substitute, in the rearranged game with Roy Hodgson's side.
Ferguson said: 'Wayne should be ready for the game on Saturday against Blackburn. We're quite confident of that and he may have a slight chance of being fit for a place on the bench on Wednesday.'
The Scot's caution is understandable – Rooney has never before picked up a hamstring problem and they are notoriously prone to relapse. The initial prognosis should have seen Rooney back for last week's game with Everton but sources at Old Trafford have confirmed they were not prepared to take any risks to jeopardise his chances of playing in the San Siro.
But a substitute appearance in a game which could send United five points clear of Liverpool at the top of the table would make perfect preparation as Ferguson plots another assault on the biggest prize in club football.