England's Six Nations campaign begins in the Eternal City on Saturday but head coach Steve Borthwick is facing some difficult selection decisions before his team's opening game.

Stalwarts Courtney Lawes, Mako Vunipola, Ben Youngs and Jonny May have retired from international duty, while several overseas players are ineligible for selection and former captain Owen Farrell is taking a break from Test rugby.

BBC Sport looks at four dilemmas facing Borthwick before England's opener against the Azzurri.

Flanker - Pearson to stake claim?

Veteran Lawes has retired from England duty and Tom Curry is ruled out of the Six Nations with a hip injury, so Borthwick's flankers will have a new look from the World Cup semi-final defeat by South Africa.

Jack Willis is based overseas with Toulouse and is therefore ineligible for selection, and Lewis Ludlam has not been included in the squad so Borthwick does not have a lot of experience to rely on.

Exeter's Ethan Roots and Harlequins' Chandler Cunningham-South have been called-up to the senior squad for the first time, while Curry's twin brother Ben and Northampton's Tom Pearson have six caps between them.

Bath's Sam Underhill has also returned to the England fold and is likely to occupy a starting role against Italy, with 24-year-old Pearson favoured by many to claim the other.

He is physically imposing in defence, tireless at the breakdown and bursts on to the ball with the speed of a centre in attack, as demonstrated by his hat-trick in the Investec Champions Cup win over Bayonne.

With Ben Earl at number eight and Underhill's skills at the breakdown it could be a well-balanced back row.

Fly-half - Ford or Smith?

Owen Farrell's decision to make himself unavailable and Marcus Smith's injury means a straight shootout between the uncapped Fin Smith and the experience of George Ford.

Smith has been pivotal in Northampton's charge to the top of the Premiership in his breakthrough season, while Ford has 91 caps and starred as England beat Argentina in their World Cup opener.

Fin Smith, 21, has showed game management which belies his years and has the physical attributes to match - sharp step, rapid acceleration and accurate distribution.

He could be the blend of flair and pragmatism England and Borthwick have been looking for.

Ford, 30, is tried and tested at Test level and has the nous to control the game against the Azzurri but the Smiths will be the future for England - and this would seem the perfect match to see what Fin can do.

Inside centre - Dingwall's time to shine?

Manu Tuilagi's power has often been the favoured option in midfield by both Borthwick and his predecessor Eddie Jones.

But the Sale centre is out with a groin injury and it is unclear whether the England management still have the 32-year-old in their plans or whether they are looking to the future.

Exeter's Henry Slade has returned to the squad after being overlooked for the World Cup and Elliot Daly can also cover in midfield, although both are better-suited to outside centre.

Bath's Ollie Lawrence would have been a natural replacement for Tuilagi but his injury has resulted in a first call-up for his clubmate Max Ojomoh as cover and is likely to finally open a door into the side for Northampton's uncapped Fraser Dingwall.

Like Pearson and Fin Smith, the 24-year-old has starred for Saints in the English top flight with his uncompromising defence.

He is not the biggest or quickest centre but is a more rounded option, and with the experience of 10 previous England call-ups behind him, he could claim the 12 berth for his own.

Wing - fresh faces to shine?

Jonny May's England career is behind him, Henry Arundell and Jack Nowell now play their club rugby in France and Anthony Watson is regaining his fitness after a calf injury which led to him missing the World Cup.

That all means England are looking for fresh impetus on the wing.

Tommy Freeman, 22, is another beneficiary of Northampton's form. He has a powerful and effective running style and is a contender to win a fourth England cap from the start.

Sale's uncapped Tom Roebuck has impressed in the Premiership and in Europe and Exeter's Immanuel Feyi-Waboso has the ability to follow captain Jamie George's orders and "put smiles on fans' faces".

He has showcased speed, power through the tackle and an eye for the tryline - with five scores in 10 Premiership matches for Chiefs this season - in a breakthrough campaign.

And those attributes could be the uncapped wing's ticket into the team after the Cardiff-born flyer turned his back on Wales.

But if Borthwick wants Test-match experience then 64-cap Daly is an assured option, while Freddie Steward could also deputise on the wing, as he did in the World Cup against Argentina, should Northampton's George Furbank be rewarded for his blistering club form with a spot at full-back.