Rugby: Selection issues await for British and Irish Lions

There are vacancies in the Lions' probable test line-up and a couple of thorny questions that the coaching staff will look to answer after the match against the Chiefs.

The troublesome areas are their back three and midfield where it's unlikely that the Lions have fixed on who they are going to select in those roles to play the All Blacks.

Clouding the issue is the head knock suffered by Leigh Halfpenny against the Maori. The Welshman may not necessarily offer the same counter attacking threat as others in the squad but he is one of the best goalkickers in the world and as such, presumably, a certainty to play if he's passed fit.

But coaches can never be sure when it comes to head injuries and Gatland needs to have a Plan B. That's why Liam Williams has been picked at fullback to play the Chiefs.

The Welshman enjoyed an impressive tour of New Zealand last year and has played well on the wing so far on this trip. A big game from him and he shifts himself into contention to start if Halfpenny is ruled out.

"The thing about the back three is that a number of players are pretty versatile," said Lions coach Warren Gatland.

"We could have left Liam on the wing and played Elliot Daly there [fullback]. It is an opportunity for him to go out there and impress at fullback. Anthony Watson did a good job coming on at fullback against the Crusaders. He's looked dangerous as well.

"So we are giving players a chance from a counter attacking perspective to go out there and impress.

"There is no doubt they [Chiefs] will come to play and throw the ball around as they typically do."

Regardless of the final make up, Gatland will feel a degree of confidence that with Halfpenny, George North, Williams, Watson and Daly all in the mix, that he will be able to put out a back three with the ability to cause a few problems.

The composition of his midfield may not be so easy to determine as it comes with a couple of different options.

Ben Te'o and Jonathan Davies have been the preferred Saturday pairing so far and have gelled well and are developing a useful combination. Te'o is growing in stature and his direct running fits perfectly within the Lions gameplan.

There will likely be some reticence among the Lions coaching staff to break that 12-13 set-up and the question will then be do they pick Johnny Sexton or Owen Farrell at No 10?

Farrell will be fit to play and is probably the front runner having shown greater control than Sexton, albeit only just. Should Halfpenny not play, Farrell's superior goalkicking would be a factor to consider as well.

But asked on Saturday what he expects the Lions to do, All Blacks coach Steve Hansen predicted that Sexton would be at first-five and Farrell at second-five for the first test.

That would give the Lions two decision-makers and two strong kickers - something they have not yet tried on this tour.

Perhaps it would be a risk to field it for the first time in a test but then again, Gatland has promised he has not exposed all parts of the Lions game so far.

They would sacrifice the bruising running of Te'o for the ability to increase their kicking options - a fair trade off maybe given the success the Lions have had with going to the air.