Chelsea are preparing to make a bid for Toby Alderweireld, with the 29-year-old failing to agree a new deal at ​Tottenham.

Alderweireld only has a year left on his current deal with Spurs, the terms of which mean that a release clause will be present in his contract if the club activate the one-year extension option. As reported by the Sun, the £45m rated defender is on Chelsea's radar after a frustrating season with Spurs.

Tottenham Hotspur v Real Madrid - UEFA Champions League

Alderweireld has only featured in 11 ​Premier League games this season, and it was reported in February that Spurs are willing to let him leave in the summer. Injury has halted his progress at Spurs this season, with Alderwiereld suffering a hamstring injury against ​Real Madrid in November which kept him out for many months.

​Manchester City and ​Manchester United were both rumoured to have been interested in Alderweireld, but City have since signed Aymeric Laporte while it's understood United have dropped their interest.

Mauricio Pochettino is reportedly after Matthijs de Ligt as Alderweireld's replacement, though Spurs face competition from north London rivals ​Arsenal and Spanish giants ​Barcelona.

​Chelsea will be looking to improve on their current squad as they look ahead to next season, and it looks like their main priority is defence, with ​Napoli defender Kalidou Koulibaly also a target for the Blues.

It's been a disappointing season for Chelsea, sitting fifth in the table with Spurs all-but out of reach in fourth - barring a shock loss to ​Watford on Monday night opening the door.