Noel Whelan has claimed Helder Costa may be “going the way of Samuel Saiz” if he is not careful at Leeds United.

Speaking exclusively to Football Insider, the ex-United forward called on the £15million loan-to-buy signing to be far more effective than he has been since his summer arrival.

The winger suffered the rare indignity of being axed from the starting XI against Luton Town today by Marcelo Bielsa, who normally only leaves out players due to injuries and suspensions.

He took the unusual step of changing a winning team for reasons other than injury by dropping Costa to the bench and starting Pablo Hernandez.

Costa’s omission was especially notable as Leeds had won each of their previous two league matches, each of which he started.

“Costa hasn’t looked like a £15million player, or anything like,” Whelan told Football Insider. “We need to see so much more from him.

“There has been the occasional glimpse of magic but not the consistency, very much like Jack Harrison last season.

“That’s something he needs to work on massively, or he’ll be going the way of Saiz. 

“Costa has much more to give. He has been a bystander at times. He needs to be far more involved and much more effective in his defensive play.”

Pablo Hernandez replaced Costa in the starting XI at Kenilworth Road after being a second-half substitute in the wins over Blackburn Rovers and QPR before the international break.

It ended a run of eight consecutive league starts for Costa, who has yet to score in 17 appearances for United since his arrival from Wolves.

Saiz quit Wolves in the middle of last season after losing his starting place, joining Getafe on loan ahead of January before heading to Girona in a permanent deal in the summer.

In other Leeds United news, it can be REVEALED that the club’s Kiko Casilla hopes rise after significant developments behind the scenes.