Borussia Dortmund are showing an interest in signing Celtic left-back Kieran Tierney at the end of the season. 

According to The Guardian, Dortmund have been monitoring the progress of Jeremy Toljan in Scotland, but have been impressed with the fullback on the opposite side for Celtic – Tierney.

The report claims that Dortmund have been blown away by Tierney’s displays at left-back for Celtic over the past few months. 

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Celtic are said to want a fee in the region of £25m for the defender, who has been brought through the academy at Celtic Park. 

If Dortmund do decide to make a move for Tierney they will face stiff competition, with Arsenal and Leicester both also said to be keen on a deal for the Scottish international. 

The 21-year-old has made over 150 appearances in all competitions for Celtic since breaking into the first-team in 2015. 

He has won seven trophies with Celtic in his career so far and is on course to add a fourth league title to his collection this season.