Forget Six Nations form, Maro Itoje can rattle the Boks | Jeremy Guscott

WHEN you think of must-go Test Lions for the 2021 series against , the first forward that comes to mind is . He will be a cornerstone of the Lions in South Africa, despite not having the best Six Nations in a disappointing England side.

Throughout his career Itoje has had a tendency to give away penalties, because sometimes he pushes the envelope a little too much. Until this season he had usually been on the right side of the decisions, and usually it is a question of very small margins.

There have been other players who have done the same, with Richie McCaw an expert at treading the fine line between disrupting the opposition and giving away penalties. One of McCaw's great advantages was that he knew the laws inside out, and, like a good golfer, he used to get the rugby equivalent of free drops, using the rule-book legitimately to get an advantage.

There were always questions after matches about McCaw getting away with murder, and it was the same with Martin Johnson, but because they were both great players they would be given the benefit of the doubt, and got the majority of refereeing calls in their favour.

Itoje is one of those who, like McCaw and Johnson, is inspirational through what he does on the field. There is no one better at making a difference when the pressure is at a peak. Whether it is lineout steals, jackalling at the breakdown, tackling, or carrying, you could put a 6, 7, or 8 on his back as easily as a 4 or 5, and he could make enough of a difference to swing a game your way.

Itoje is one of those exceptional players who are as good in defence as they are in attack, and it gives him an edge in Lions selection. For example, his England teammate Sam Underhill is seen as a great defender, but as an openside flanker he does not do enough in attack to be seen as an all-rounder – and he needs more runs like the one that saw him come so close to scoring a spectacular try against New Zealand in 2018.

If you are talking about locks, then the great all-rounder is New Zealand's Brodie Retallick. He has the great ball skills of a basketball player in attack, but he makes the same impact in defence.

England lock Maro Itoje
Turning point: Maro Itoje is carried over the line. Visionhaus/Getty Images

Itoje would not be out of place in the New Zealand pack, and he has similar capabilities to Retallick in terms of being an inspiration. We look at Faf de Klerk doing the same for South Africa at scrum-half, and in my time it was Joost van der Westhuizen doing it. It is players like those who have the skill sets and the rugby brains to become legends – and Itoje is on that same path.

Itoje already has most of the credentials having won a Six Nations Grand Slam and two more Championship titles with England, as well as multiple European Cups and English titles for Saracens.

In fact, the only things missing from his CV are winning a Lions tour and a World Cup.

He has shown that he is a player who can thrive under the heaviest pressure, with the drawn Lions series against the All Blacks in 2017 a clear example.

The South Africans are another world champion side, and plenty of their forwards will challenge Itoje this summer, including Pieter-Steph du Toit, who won the player of the year in 2019, and is big enough and fast enough to play in either the second row, or the back row. However, Itoje ran him close for the award, because over the last five years he has been one of the most consistently outstanding forwards in the international game.

Itoje enjoyed first-year success at Test level with the Slam, and then the three-nil series win over , and since then he has sustained it by achieving more by the age of 26 than 90 per cent of top players will manage in their entire careers.

It is for those reasons that Itoje should have guaranteed his spot on the plane to South Africa, and also the Test team. The only hurdle is the high individual penalty count which put a question mark against his name after England's Six Nations games against Scotland, , and Wales.

He was part of an England team which lost momentum, and that is why early on in the tour he will need to being in stonking form. The Lions will need him to be at his best in winning lineout ball, carrying well, and nicking turnovers.

The only negatives that will be acceptable are a single lineout loss per match, and the same in terms of conceding penalties. His worst game has to be a 7/10. He dropped below that in the Six Nations, and that is not world-class – and nor is it enough to retain a reputation for constant improvement.

I'm convinced Itoje is so good a player that he will rise to the occasion. When he is at his best he not only gets in the starting team, but also brings that added extra.

Whether it is winning those key charge-downs and turnovers, or stealing lineouts, or perfectly timed tackles, the Lions need what Maro Itoje had to offer.

Picking a key back is not quite as straightforward, but my thinking is that the Lions will have to put at 10, or maybe Johnny Sexton, because you could not have either of them at 12 with Damian de Allende running down that channel. He would be too much for either.

The good news for the Lions is that Robbie Henshaw was in inspired form for in the Six Nations, and could be the answer at 12. Physically he is a unit, and has some heft to him in defence and attack. He is no slouch, and while he may not be quite as fast as De Allende, he is no frills and no spills.

Henshaw carries very hard, and in defence no one will run over him – which is exactly what you need at inside centre against South Africa.

The kicking game is not necessarily his greatest strength, but his running and tackling are what matter most – and he's good under the high ball like a lot of Irish players who have also played Gaelic football.

What I like most is that Henshaw has the ability to make that big, strong inside centre burst over the gain-line. There is no better way of setting up your forwards, and he's capable of knocking the opposition over in a way that Farrell is not.

I only saw Farrell make one good hard run at inside centre during the Six Nations, where he cut in-field from a lineout – but he then almost lost the ball. The coaches may have a bigger picture in mind, which might mean Henshaw playing at outside centre. However, the Irishman could be crucial at 12, because, although the have improved their fitness and have a winning mentality, I don't believe we will see anything but route one from them.

Against South Africa in 1997, Scott Gibbs would not be knocked over. He wanted to hurt them legally in defence, and he did, and it was the same when he was carrying. He was going for a home run every time he got the ball, and the South Africans found him hard to stop.

You have to beat South Africa at their own game of kick and defend. I am a big advocate of Henshaw for those reasons, and his form almost demands that 12 shirt.

When you turn the pressure on South Africa, penalties come into play, and then the 2021 Lions need their own version of Neil Jenkins, who in 1997 had the cool head, technique, and accuracy to see us over the line.