Lions: Five dark horses for selection from the Premiership

Warren Gatland will name his British & Irish Lions squad on Thursday for this summer's tour of South Africa, where the world champions lie in wait.

Gatland is unbeaten in his time as head coach and crucial to effecting his gameplan in Australia and New Zealand have been the likes of Jonathan Davies and Alun Wyn Jones – a common connection to his success with Wales.

But in each of the three Tests in New Zealand, England boasted a majority in the selected 23.

Four years on and a fifth-place finish in the Six Nations has left many of England's players facing questions over the merit of their form.

So what if being capped by England this year comes at a cost for Eddie Jones' Lions hopefuls? Could Gatland's frequenting of Premiership grounds over the course of this season serve those that have starred for their club instead of country?

Marcus Smith – Harlequins

Time and time again, the Brighton College graduate has come up big when Harlequins have needed him most to propel them into serious semi-final contention.

Quins attack coach Nick Evans has been effusive about Smith's talents, saying praising his ‘high' ceiling, but he is yet to be tested at the Test level.

At 22, Smith's age may be of detriment even before mentioning his competition at the position in Owen Farrell, Dan Biggar and Finn Russell.

But Farrell was selected as a 21-year-old for the Lions in Australia eight years ago and questions over the Springboks' balance at fly-half, with Handre Pollard returning from a ruptured ACL on Saturday, potentially helping Smith's cause.

South Africa's stout defence showed few signs of weakness at the World Cup. Yet they haven't played a match since beating England in Yokohama and Jacques Nienaber has been promoted to head coach as Rassie Erasmus reverts to a director of rugby role. That may lead to Gatland and attack coach Gregor Townsend opting for Smith to be their exploitative nuisance to the Boks' line speed.

Piers O'Conor – Bristol Bears

Bristol Bears have stayed on track at the top of the Premiership summit through the loss of Steven Luatua, Charles Piutau and Semi Radradra at times this season.

Central to their upturn in form has been the performances of versatile back Piers O'Conor, who has elevated his play to ‘world-class levels' in the words of Pat Lam.

A starter for England in their uncapped international match against the Barbarians in 2019, O'Conor's ability to play anywhere in the outside backs would serve as a major benefit for Gatland's cover at centre, wing and full-back – just as Elliot Daly did four years ago.

Dave Ewers – Exeter Chiefs

A certainty for England's tour of the Americas this summer if his outside shot at the Lions is not blanked by Jamie Ritchie and Tadhg Beirne.

Tackles all day and a monster at the breakdown for the Chiefs' robust pack, Ewers was firmly on England's radar under Stuart Lancaster when he appeared for the Saxons in 2015 and has been a figure of consistency ever since at Sandy Park without being deemed worthy of a Test cap.

The trickle-down of Gatland having so many rich options at lock could hinder Ewers and other natural blindside flankers, given Maro Itoje and Beirne being able to interchange between the second row and back row.

Thursday's announcement will be a key indicator of whether Gatland will view the lineout as a point of attack or collisions.

Cameron Redpath – Bath

A future Lion – but could South Africa come too soon for the 21-year-old having recently returned to the pitch following nine weeks out?

Equally a standout in both defence and attack on debut for Scotland in their Calcutta Cup win over England this year, Scotland's medical team identified a neck injury that only became apparent in the days following the 11-6 win at Twickenham, causing Redpath to miss the rest of the Six Nations.

Although new to senior Test rugby, Redpath has long been viewed as one of the next big things going back to his time at Sedbergh School. Bath now have high hopes for a 10-12 combination of Orlando Bailey and Redpath to ascend them back into serious domestic and European contention – so don't be surprised if these two former age-grade prodigies are big names in the next Lions cycle to run to 2025.

And if injury should befall Robbie Henshaw, who else holds the all-round attributes to be the Lions No.12?

Zach Mercer – Bath

Redpath's Bath teammate is in the midst of some of the best form of his career in the lead up to his departure for Montpellier – being the main man in Stuart Hooper's pack week in, week out to outshine Lions talisman Taulupe Faletau.

Indeed, the two-Test No.8 is one of three players in his position who were left to play Premiership rugby instead of the Six Nations in Sam Simmonds and Alex Dombrandt. The latter could also take a place in this list as a player who is joint-second in the Premiership's tries and clean break charts.

What stands out for Mercer is his improvement in defence, making more tackles this season than Simmonds, Jono Ross and Daniel Thomas in the league this season. Add to this the leading total of beaten defenders for any forward in the Premiership and the Montpellier-bound dynamo may be a surprise inclusion come Thursday.