Why Marcelo Bielsa will remain cautious in his approach with Leeds United youngster Jack Clarke

Leeds United winger Jack Clarke celebrates at Villa Park.

Clarke was the catalyst for an extraordinary second half at Aston Villa on Sunday, setting up a fightback which ended with Leeds snatching a 3-2 victory in the fifth minute of injury-time.

Bielsa turned to Clarke, as he has repeatedly in recent weeks, to make a difference with Leeds trailing 2-0 at half-time.

The 18-year-old replaced Jack Harrison and scored his first senior goal on 55 minutes, the youngest player to find the net in the league for Leeds since Simon Walton in 2005.

Despite his obvious talent and consistent impact, Clarke has been restricted to substitute appearances under Bielsa, playing seven times.

Bielsa admitted to being surprised by Clarke’s influence but said he was wary of exposing him in a way which would potentially “hurt” the academy youngster.

“He was very important because he scored the first goal,” Bielsa said. “He gave enthusiasm to the team.

“When I started to look at his skills I didn’t imagine that he could make the difference as he’s making the difference now. As with every young player I think he can improve a lot. He has to confirm his level and show what he is capable of.

“We know that a feature of any big player is to maintain the same level of performance. He’s a young player and we have to manage his playing time. That’s my opinion. If we build an imagine which exaggerates his capabilities, instead of helping him we will be hurting him.”

Clarke laid on the winner in another precious victory over Sheffield United at Bramall Lane on December 1, again as a result of a half-time introduction, and he began the recovery at Villa by skipping past Villa defence Ahmed Elmohamady and firing into the net.

“Playing as a substitute he has showed his capacity to make the difference during games,” Bielsa said. “We will have to evaluate if it’s convenient or not for him to start.

“With young players when they make a good performance they generate positive comments, When they don’t make good performances, they create (negative comments). That’s why I think we have to manage his development.”