London, June 22 : Manchester United goalkeeper David de Gea has faced the wrath of pundits as well as former United players after failing to perform as per expectations in recent times and former skipper Gary Neville believes de Gea must go back to the basics. "He's got to go back to basics ... He was the one player United could rely upon for the last four years but he's not the same," Neville said on his podcast. "When form drops for six months it's a blip but when it goes on for a year you start to worry. When it goes over two years it becomes more permanent." Former Manchester United captain Roy Keane lashed out at Harry Maguire and de Gea for their poor performances in the team's 1-1 draw against Tottenham Hotspur in the English Premier League. "I'm shocked at that goal," the former United captain said on Sky Sports. "I've watched a lot of football over the years, but to give that away, I'm fuming. I can't believe (Luke) Shaw heads the ball up and then runs forward, I'm staggered at Maguire, staggered that an international player can get done like this, and I'm sick to death of this goalkeeper. "This is an established international goalkeeper. I'm flabbergasted. There's got to be something going on at half-time. If I was Ole, make some changes, get some lads off the pitch, some of them are going through the motions at the moment," he added. /IANS