Noel Whelan claims there are still doubts over Leeds United winger Helder Costa despite a dazzling display against Stoke City.

The former Whites striker, speaking exclusively to Football Insider assistant editor Russell Edge, was left raving over the 26-year-old in what was his first game as a full Leeds player.

Leeds confirmed this week that the Portuguese winger had officially joined the club on a permanent basis after agreeing an obligation to buy when they signed him on loan last summer.

Whelan admits he was thoroughly impressed with what he saw on Thursday evening but says that the £16million fee will hang over his head if he cannot deliver on a regular basis.

Speaking for the first time about the permanent signing of Costa, the ex-striker told Football Insider: “That’s the secret – can he maintain that level of performance and quality that he’s shown?

“We know he’s got it there, we’ve seen it in spurts throughout games and throughout the season but he needs to be more prolific in the job he does.

Subscribe to Football Insider TV now

“Driving in for the penalty, that is what we want from Helder Costa, that is why we’re paying money for him, that is what he’s good at but we need it more than once in 90 minutes.

“The goal, again, great movement, prolific in front of the goal – that is what we’re paying £16million for. Throughout the whole second half, he was excellent – that is the Helder Costa we’re paying £16million for but he must keep that level of performance or else it’s going to be £16million questioned.” 

Costa has played 44 times across all competitions for Leeds since joining on loan from Wolves, with five goals and seven assists under his belt.

Thursday’s 5-0 win over Stoke sent the Whites back to the top of the Championship with four games left to play.

In other Leeds United news, Noel Whelan has told Football Insider club should use potential £18million cash injection to sign Ben White.

PLUS: Subscribe for free to our brilliant new YouTube channel for daily videos, interviews with our top pundits and special guests, and all the latest insight into the club you love.