Tottenham are watching Celtic defender Kieran Tierney.

The Sun says Spurs have stepped up their pursuit to sign Tierney.

Mauricio Pochettino sent a top European scout to watch the 20-year-old in action against Bayern Munich on Wednesday.

Although Munich triumphed 3-0 against the visitors, the left-back put in a good display at the Allianz Arena.

Spurs have been long-term admirers of Tierney, but he has attracted a wide range of interest from a host of Europe's biggest clubs.

Tottenham scouts viewed him at the start of summer against Astana and have been monitoring his progress since.