Arsenal legend Tony Adams believes that the Gunners made a mistake in selling forward Robin van Persie in the summer.
The Netherlands international joined Arsenal's Premier League rivals Manchester United, where he has scored seven goals in eight competitive appearances so far this season.
"I thought Robin was a mistake," Adams told the BBC. "I think he could have played for four or five more years.
"I hope they do go on and win everything. Realistically, I think they will fall short again. I wouldn't have made that decision [to sell Van Persie].
"Because I do believe if you want to win major trophies you need [the] best players."
Adams played for Arsenal between 1983 and 2002 and won the English first division title on four occasions and the FA Cup thrice.