Last updated on .From the section Football

Welbeck opened the scoring at Old Trafford

Manchester United forward Danny Welbeck has been ruled out for four to five weeks after suffering a hamstring injury in the 8-2 win over Arsenal.

Welbeck, who has been in fine form this season, earlier opened the scoring, his second of the new campaign, before pulling up injured in the 35th minute.

His injury means he will now miss England's Under-21 games against Azerbaijan and Israel in September.

"It is a loss for us and for England," boss Sir Alex Ferguson told BBC Sport.

Welbeck joins Rafael da Silva (shoulder), Rio Ferdinand (hamstring) and Nemanja Vidic (calf) on the sidelines for United.

"Danny complained of a tight hamstring before he actually pulled it and we couldn't get [Javier] Hernandez on quick enough," said Ferguson, following the rout at Old Trafford.

"It is a shame for Danny but it [his absence] will be around four to five weeks."