Boudewijn Zenden says criticism of manager Louis van Gaal from ex-players is not helping Manchester United's situation and claims the Christmas period could be make-or-break for his fellow Dutchman.
The pressure has been cranked up on Van Gaal following a six-match winless streak and a run of three consecutive defeats, including a loss to Wolfsburg that eliminated United from the Champions League, in their last three outings.
There has been speculation United could turn to Jose Mourinho, who left Chelsea by mutual consent last week, to replace Van Gaal if results do not improve.
United greats Paul Scholes and Roy Keane are among those to have taken aim at Van Gaal's methods this season, public criticism Zenden believes has been unhelpful.
But the former Netherlands international - who played under Van Gaal during his time at Barcelona - knows the manager must pick up points in matches against Stoke City, Chelsea and Swansea City to disprove his doubters.
"He has the crowd against him and there's pressure on him and the management. Ex-players having their say isn't making it any easier," Zenden told Omnisport.
"Articles about saving his job are driven by media need for new stories.
"But only wins can save him. The December games come thick and fast and can make or break a season."
Although speculation over Van Gaal's future is rampant, Zenden believes United's hierarchy are satisfied by the manager's work.
"People at United are happy with Van Gaal and what he's doing behind the scenes," he added. "Using the youth teams and restructuring completely."