The Spaniard, who has had an inconsistent term since joining the Red Devils in 2011, failed to punch clear the ball which led to a Clint Dempsey equaliser in yesterday's 1-1 draw at White Hart Lane.
"Manchester United's hopes of regaining the Premier League title will always be in jeopardy if David de Gea keeps making mistakes like the one against Spurs and he must surely be on his last chance now," Hansen writes in The Telegraph.
"Without a doubt he cost them three points and this is a crucial stage of the season where Sir Alex Ferguson needs to decide whether to stick with him or take him out the firing line.
"The result at White Hart Lane could prove a season-defining moment and United cannot afford to be drawing games when they should be winning them."
Meanwhile, the United team have flown to a Qatar training camp for four days.