Arsenal striker Welbeck undergoes knee surgery

English football club Arsenal on Thursday announced that striker Danny Welbeck has undergone surgery on his left knee after being unable to sufficiently step up his rehabilitation work.

The 24-year-old England international, signed from Manchester United in September 2014, has been working throughout the summer to recover from the injury sustained at the end of April.

"It had been hoped he would avoid surgery but after increasing his training workload, the injury to his cartilage did not respond as well as hoped and the decision was taken last week for him to undergo surgery by a leading specialist in the field," Arsenal said in a statement.

Welbeck is now expected to be out for a period of months.