London, Sep 10 (IANS): Former England batsman Kevin Pietersen has said that Jack Leach has swiftly become a joke as he has been unable to perform his duties as the main spin bowler.

Leach had become a superstar after scoring one run during the match-winning last-wicket stand with Ben Stokes at Leeds in the third Ashes Test at Headingley.

"It's doing my head in that a bloke who's supposed to win games for England is becoming a laughing stock. You've got people in the stands taking the mickey out of him, wearing masks and fake glasses. Commentators are talking about his Specsavers deal," Pietersen wrote for online bookmaker Betway.

"England are losing an Ashes series and he's only taken eight wickets at 30 in three Test matches. It doesn't look like he's troubled anyone," he added.

"Now I'm not saying that you don't do these things. It can be good for team spirit to have a bit of fun. But, from my side, I want to win. I don't want to see the crowd talking about how funny he is. I want to see him winning matches for England with his bowling," the 39-year-old expressed.

Pietersen also questioned if Jason Roy could make it as a Test batsman. "I'm not saying he can't get there. I think he's an amazing player. But he needs to sort out his technique - it isn't good enough for Test cricket," he concluded.