Tierney is one of the best defenders in the Scottish Premiership and is one of the most promising young left-backs in Europe.
The 20-year-old has established himself as a regular in the Celtic first team, and his performances in the Champions League so far this season have been hugely encouraging and impressive.
Former Tottenham and Scotland international forward Brazil, who now works as a presenter on talkSPORT and admitted in The Sunday Post in July that he is red-hot Celtic fan, has suggested that if United came calling for him, then Tierney would find it hard to turn down the move.
Brazil wrote in The Sunday Post: “Let’s just say the United gaffer has a look at Tierney, thinks to himself: ‘He’s my guy,’ and slaps in a £25-million offer.
“Does Celtic Chief Executive Peter Lawwell knock that back because Kieran Tierney is happy at Celtic?
“Does major shareholder Dermot Desmond let him do it? Not a chance. So let’s assume that Jose’s offer is accepted, and the ball is in Kieran’s court.
“Does he really look at the chance of a move to Manchester United, the chance to play under one of the best managers in the world, on the biggest stage week-in, week-out, testing himself against the best – and say : ‘No’, because he’s happy at Celtic? I don’t think so – and I should know.”