Former Liverpool and Tottenham Hotspur midfielder Jamie Redknapp has slammed Marcus Rashford for his lacklustre performance during Manchester United’s Premier League 1-1 draw with Brentford on Saturday. Redknapp said the England forward was walking around during the encounter at the Gtech Community Stadium like it was a bit of fun. Recall that Rashford featured against Brentford as Mason Mount broke the deadlock with his first Man United goal deep into stoppage time. However, Kristoffer Ajer hit back in the 99th-minute to salvage a point for the host. “They [Man United] have been so bad tonigh…