Adil Rashid still England's best spin option, says Shane Warne

Rashid got a surprise call-up to England's Test side for the recent series against India, which Joe Root's boys won 4-1. He picked up only three wickets in the first Test, and achieved a rare feat at Lord's by becoming the 14th player ever to go through a Test without batting, bowling or being involved in a dismissal on the field.

In the remaining three Tests, he could only manage seven more wickets and also remained wicket-less at Ageas Bowl where his spin partner Moeen Ali, on his return to the Test side, snared nine wickets.

Warne feels Root needs to show confidence in Rashid. "It's very important that the captain backs you," he told ESPNcricinfo at an event at The Oval.

"Early on in the series, Joe Root needs to throw the ball to Rashid. Bowl him first change, or even open the bowling with him if the conditions suit in the second innings. Let him know he's the No.1 spinner and that he's got all the support of the captain. That is crucial."

Rashid's brilliant delivery to dismiss KL Rahul on the final day of the fifth Test at The Oval had drawn comparisons with Warne's own "ball of the century".

Good at that delivery was, "I don't think one ball justified the whole selection," said Warne. "It's about what impact you have through the series. Does the captain have confidence to bowl you when it's tough, or when the conditions suit, or as a change-up when nothing's happening? Because a leg-spinner makes something happen.

"Even when he doesn't bowl well, he can still make something happen. I hope they stick with him because all his wickets were invaluable through the series.

"England have got so many all-rounders in their side. People say England don't need six bowlers, but I like having Moeen Ali in the top six. He's a batsman who plays as a second spinner, so you've really got five bowlers plus Moeen. And that gives you the flexibility to keep Rashid, because I still think he's the best option."

Bowling to prive his worth will put Rashid in a difficult state of mind, according to Warne. "You can't explain to someone what it's like when you know you're playing in the next game.

"If you are playing for your spot all the time it's very, very difficult. You are bowling to not make mistakes. And you're bowling to stay in the team, not do a bad job, to keep it tight. If you know you are playing in the next game you have a bit more leeway. You can get a bit more experimental, you'll try a few more things, you'll get a bit more aggressive.

"I think that's what Rashid needs to do. Going to Sri Lanka, he knows he'll play in that next game, which is so important. He's got his confidence up, he got a couple of great wickets in this last Test match to help England win. So I'm looking forward to some big things. Hopefully he'll go on and on from here."