Atletico Madrid have joined the interest in Celtic fullback Kieran Tierney.

The Sun says Atletico will watch Tierney in the Scottish Cup final and join the race for the Celtic full-back.

The Spanish giants are set to compete with Manchester United and Tottenham should the £20million-rated youngster become available.

Bournemouth are also interested in taking the 20-year-old to the Premier League and will offer a direct route to the first team.

But Atletico will signal their serious interest by sending representatives to Saturday's showpiece against Motherwell at Hampden Park.

They will watch the Scotland left-back attempt to complete the treble in a season that has seen interest in him increase.