Sam Warburton poses arguably Warren Gatland's biggest Lions selection dilemma

Two-time British and Irish Lions captain Sam Warburton believes the Guinness Six Nations has three world-class openside flankers.

Following a stellar performance in a historic win over England at Twickenham on Saturday, Warburton hailed Scotland’s Hamish Watson’s performance as “phenomenal” and ranked him among Justin Tipuric and Tom Curry in a select group of world class No7s in the competition.

“Re-watching the Scotland game in readiness for this weekend's game. Have to say, Hamish Watson was phenomenal. With Tipuric, Curry and Watson you have three world class 7s.”

With his Calcutta Cup performance, Watson displayed his Lions credentials to head coach Warren Gatland. The Edinburgh flanker was already in the reckoning to travel to South Africa in the summer, but he boosted his chances considerably at the weekend.

Watson is making a late run for the tour given the lofty standard Tipuric has maintained over the past decade and Curry’s surge in status since becoming an England regular in 2018.

Sam Warburton and Hamish Watson /Getty

The problem Gatland faces is choosing which No7 to take with him, and when including other options like Sam Underhill, the decision is only complicated further. All three players Warburton mentioned could well be part of the squad in the summer, but only one can start.

Gatland has not been averse to fielding two opensides in his pack in the past, as he did with Warburton and Tipuric when in charge of Wales. But England experienced the pitfalls of that approach first hand in the World Cup final in the way they were outmuscled by the Springboks. It would be surprising if the Kiwi also explored that avenue in South Africa.

The Scot got the better of Curry in London, and now comes head-to-head with Tipuric at Murrayfield on Saturday, meaning Gatland’s back row landscape may be different come the end of the weekend.