Leeds United's talismanic Swedish centre back Pontus Jansson has left the club, joining Championship rivals Brentford for an undisclosed fee.
Speculation now builds as to who will replace him at the heart of defence.
There are a number of options among the current squad from new signing Ben White to existing first teamers Gaetano Berardi , Kalvin Phillips and others.
When it comes to the under-23s, three young centre backs have left the club so far this summer in the form of Hugo Diaz who was released, Aapo Halme who was signed by Barnsley and Liam Kitching who has joined Forest Green Rovers.
So who are the young players at Leeds who will be hoping to break into the first-team in the current weeks or months?
Pascal Struijk
The leading contender among last season's title winning Under-23s to make the step up to the first team this season, the 19-year-old Dutchman is yet to make his first-team debut but made several appearances on the bench towards the end of last season. Struijk was signed from Ajax in January 2018 and made an immediate impression on his debut, scoring a goal and an own goal for the Under-23s against Birmingham.
Leif Davis
Signed from Morecambe in July 2018, Leif Davis made a surprise first team debut when Barry Douglas was taken ill before kick off at Villa Park in December 2018. He featured on the bench several more times throughout the season, as well as regularly playing for the under-23s. Although the 19-year-old usually plays at left-back, he is also an option at centre-back.
Conor Shaughnessy
Although Shaughnessy has featured for the first team since signing from Reading in 2016, he spent the second half of last season on loan in Scotland at Hearts and it seems unlikely that the 23-year-old will be Bielsa's solution to the potential gap at centre-back.
Oliver Casey
The 18-year-old Leeds-born defender was part of the league winning under-18s in the 2017/18 season and signed his first professional contract in November 2018. The first team might be a step too far for Casey at this stage but he's set to be a regular for Carlos Corberan's under-23s.
Charlie Cresswell
The son of Leeds United's head of academy coaching, and former striker for the Whites Richard Cresswell, Charlie had a successful season for the Under-18s in 20018/19, receiving national recognition and scoring 10 goals from the centre back position. Again, this season might be too early for the 16-year-old to make it into the first team but he'll be looking to break through into the Under-23s this season.
