Despite Celtic's excellent transfer business, Nevin expressed his disappointment at seeing Tierney's talent go to waste in North London before he left the Premier League. Nevin believes Tierney was a better left-back than Andy Robertson, who has done well with Liverpool. According to Nevin, Tierney was just as good as Robertson at getting forward and adapting to different situations.

Neivin acknowledges that Tierney has not achieved as much as he could have, partly due to injuries that held him back. However, he understands Tierney's decision to join Celtic, which offers him a stronger chance at winning silverware domestically and playing European football.

Neivin sees Celtic's opportunity to play Champions League football as a positive aspect of Tierney's move. He notes that Celtic pushed Bayern Munich all the way in Europe last season, which shows that they are a competitive team.

Neivin concludes that Tierney did underachieve, but it's not due to any fault of his own. He believes that Tierney is swapping the substitutes' bench for a place where he can still play Champions League football and be happy.