Van Persie is expected to complete his move to Old Trafford within the next 24 hours after Arsenal accepted a bid of around ?22 million ($34 million) for their captain.
The Holland international scored 37 goals for Arsenal in all competitions last season and his departure is a significant blow to their hopes of ending a seven-year trophy drought.
But Belgian centre-back Vermaelen, a likely candidate to replace van Persie as captain, insists Arsene Wenger's side must ignore any frustration at the striker's exit and focus on proving they can win without him, starting with Saturday's Premier League opener against Sunderland at Emirates Stadium.
"He was fantastic for us in the last year, scored lots of goals and I am disappointed he is going, but we have to focus on the next season with Arsenal," Vermaelen told Sky Sports News.
"We have to fight and I am confident we have a squad to win something.
"We start Saturday and this is all clear now, Robin is leaving and we have to move on."
Source: AFP
Source: AFP