Leeds United fans are growing increasingly frustrated by the lack of transfer activity at Elland Road this summer.

So far during the close season, Leeds have only managed to bring in two players - both on loan from Chelsea - in goalkeeper Jamal Blackman and midfield man Lewis Baker.

Leeds have seen target after target slip out of their grasp with their pursuit of a striker proving to be the most problematic.

Moves for Britt Assombalonga (Middlesbrough), Abel Hernandez (free agent), Matej Vydra (Derby County) and Jonathan Kodjia (Aston Villa) have all hit snags for various reasons.

And to make things worse, Leeds are at risk of losing one of their brightest young prospects.

Ronaldo Vieira has been linked with a move to Premier League new boys Cardiff City and the academy product could depart this summer.

The 20-year-old central midfielder has been an important part of Leeds' squad for two years but is wanted by the Bluebirds.

If the England under-21 international does leave, here are three players who could follow him out the door.

Fellow central midfielder Murphy could be given a chance to impress in pre-season after two successful loan spells with Burton Albion in the Championship.

But with the likes of Baker, Adam Forshaw, Eunan O'Kane, Kalvin Phillips and more in the middle of the park, the 28-year-old is likely to be surplus to requirements.

Former Belgium under-21 defender De Bock joined Leeds last January but has failed to make an impact.

Unless Bielsa plans to recreate him in the left-wing-back role - which Tom Pearce is more likely to get - the 25-year-old could be set for a summer exit.

Sacko completed a permanent move to Leeds last summer but struggled to make his mark on the first-team.

The Frenchman now needs to leave to further his career as there are many players ahead of him in the pecking order.