Warren Gatland and his Lions lieutenants will soon be assembling to make their final selection decisions, poring over each position to pick the squad to tour New Zealand. This 37-man group will be announced on April 19.
Next up on our run-down is the pivotal role of tighthead. Gatland is likely to take three men to battle over the Test No 3 shirt – but there is a plethora of contenders. Here they are:
Most people's favourite to start against the All Blacks. It's hard to believe Furlong is just 24 and only made his Ireland debut in 2015. And yet, in the space of two years, he has elevated himself into the pantheon of world-class No 3s.
It can be argued that tighthead prop is the most important position on the pitch and they truly are worth their weight in gold when a good one comes along. Ireland, and by extension the Lions, are lucky to have Furlong.
As mentioned when previously pondering the loosehead and hooker positions, there is a very strong chance the Lions will field an all-Ireland front row for the Test series - McGrath, Best, Furlong - and it's hard to argue against it, especially Furlong's inclusion.
His stats are off the chart when compared to his rivals for the jersey. And the one that really stands out is percentage of scrums one off Ireland feed. Most players hover around the 90 mark. Furlong's figures read 98 per cent. In other words, he almost always guarantees you a dominant scrum.
He also rarely concedes penalties - four in his last 13 games - and has a very high tackle completion count. Furlong may only last around 50 minutes before needing to be replaced, but when the Lions have a bench full of international quality, he can empty the tank on his All Black opponents knowing the cavalry will be on its way.
Leicester and England stalwart Cole is Furlong's nearest rival for the starting No 3 shirt. At 29 year's of age and 74 caps for England, Cole has vast experience and toured with the Lions in 2013.
He is always one of the first names on the England team sheet and is one of the fittest players in Eddie Jones's squad.
Most prop forwards are hauled off puffing and blowing on the hour mark, but not Cole. On average, Cole will play 70 minutes per game before being replaced, usually by 'finisher' Kyle Sinckler. It is a massive boost for any head coach to know that his tighthead can keep packing down for that long.
There are negatives to Cole's game, though, that may mean he finds Test-match minutes limited. His average number of carries per game is the lowest of all the Lions contenders - just 2.7 per 80 minutes - as are the number of tackles he makes. A tackle completion rate of 87 per cent is also not high enough.
However, it is his propensity to concede penalties that is the biggest worry. And something the Lions cannot afford. Since the 205 Rugby World Cup, Cole has played in 18 internationals and conceded 33 penalties. Not all of them resulted in points but if they had it would total 99!
If Cole is going to claw his way ahead of Furlong in the tighthead pecking order he is going to have to cut out the infractions because the All Blacks will ensure the referee is hot on the scrum, especially if Cole is playing.
A bit of a bolter but the young Englishman has a really strong chance of being on the plane because he offers something different from the other options - pace and mobility.
The 24 year-old will not be a starter, not with Furlong and Cole in the squad, but there is every chance he will be on the bench for the Tests because of what he has done for England as a 'finisher'.
His carries per game (13.3) are almost double that of his nearest rival - Furlong - and he possesses considerable speed for a big man. Bringing Sinckler on with an hour on the clock, the game opening up and tired bodies slipping off tackles, makes tactical sense. Sinckler is the tighthead version of Mako Vunipola.
On the downside, he will need to work on his tackling. A 74 per cent completion rate is far too low and there are also question marks over his inexperience - Sinckler has never faced the All Blacks having only made his debut in 2016.
The likelihood of Nel touring with the Lions is very slim, unless he can somehow prove his fitness within the next couple of weeks.
The Edinburgh tighthead damaged an intervertebral disc in his neck last year which ruled him out of the Six Nations and pretty much the entire domestic season.
The things is, when fit he is a world-class tighthead and was, until the blow, one of Scotland's few guaranteed Lions for the summer tour to New Zealand.
With so much uncertainty around a serious neck problem - particularly serious for a prop forward - you have to consider him a major doubt, but if he were to make a remarkable recovery, a Lions tighthead triumvirate of Furlong, Cole and Nel would bring incredible strength in depth.
The South African-born Scot's win percentage on Scottish feed is in the 90s and he will always guarantee a stable scrum, very rarely taking a backward step.
The Welshman is a confidence player. When his tail is up he is one of the most destructive tightheads in world rugby, but when things aren't going so well he struggles. Warren Gatland, though, will know how to get the best out of the 24 year-old.
If Furlong and Cole are the certainties, Lee is battling with Sinckler for the third and final spot. Unlike Sinckler, his tackle completion rate is high, a vital attribute in a series where defence will decide who comes out on top.
However, like Cole, he has a habit of giving away penalties - 20 in 17 games since the World Cup. His percentage of scrum wins on own feed is also the lowest of all the tighthead contenders.
At just 21, Fagerson is probably a little too wet behind the ears to tour New Zealand with the Lions but as he proved with Scotland during the Six Nations, if you're good enough you're old enough.
Should Fagerson travel, he would undoubtedly start off as a midweek player, tackling the Crusaders, Hurricanes, Chiefs, Highlanders and Blues, while giving the likely Test starters some valuable rest time.
And his young legs, impressive engine and considerable size could make him a valuable squad player.
Who are the likely tightheads?
Tadhg Furlong and Dan Cole are certainties, and Gatland will need to take three. It would have been Nel if fully fit but it will probably be Sinckler, who has the edge on Lee.