Brennan Johnson’s recent performances have been a cause for concern amongst Tottenham Hotspur supporters. The 22-year-old struggled at Old Trafford on Sunday and endured a tough afternoon while up against Aaron Wan-Bissaka. Johnson arrived at Tottenham for a fee worth £47.5 million on deadline day over the summer and has shown glimpses of his quality. Four assists and one goal in 15 Premier League appearances isn’t exactly bad going for a young player finding his feet at a new club. But off the back of disappointing displays against Burnley and Manchester United over the past 10 days, the Wels…