The England international was told by the Red Devils manager Louis van Gaal that his services are no longer required at Old Trafford. Meanwhile, the Gunners manager Arsene Wenger was in look for a striker after Arsenal star Olivier Giroud’s long-term injury.
Welbeck wanted a permanent transfer and left his boyhood club and signed for the North London side. He will wear the No 23 shirt at the Emirates Stadium and was found holding Arsenal shirt after completing his transfer.
The 23-year-old could make his debut his Arsenal debut during the Gunners’ next Premier League fixture against Manchester City.