Who should start for Rangers - Borna Barisic, Jon Flanagan or Andy Halliday?

One area, however, where the Rangers boss has stuck with what was already at his disposal is on the left side of defence. Borna Barisic and Jon Flanagan seem to be the main contenders for the spot in Steven Gerrard's starting XI, while Andy Halliday is also available to slot in as and when required.

Rangers are certainly well-stocked in this department but the issue for Gerrard is that none of these three players have made the position their own. All have their positives and their faults, and none have put forward the case to be first choice particularly convincingly.

Barisic, in particular, is often the target of Rangers fans' frustrations. Signed for around £1.5 million last summer, the expectation from the Ibrox support was that the 26-year-old would be a first-team regular for Gerrard's side. It hasn't quite worked out that way, however: the Croatia internationalist has struggled for consistency but has shown flashes of brilliance during the last year or so.

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The graphic above details Barisic, Flanagan and Halliday's stats from last year and this season, and highlights the varying skill-sets that the trio possess. As we can see, Barisic has clear issues defensively: he has the lowest tackling rate (and success rate) of the three left-backs, commits the most fouls and completes the fewest interceptions on average. Both Flanagan and Halliday comfortably out-perform the Croatian, defensively-speaking, but both have their own issues going forward.

Flanagan, in particular, rarely contributes in attacking phases of play for Rangers. Halliday is a decent option in this regard, but for games where Rangers expect to have lots of the ball and don't expect to have too much to worry about in defence, Barisic is the clear option. The 26-year-old hits far more crosses than either Flanagan or Halliday - although, somewhat surprisingly, Halliday actually has a marginally higher success rate - and contributes far more in terms of dribbles and assists.

This is the main issue facing Gerrard at present. While he has a variety of options in just about every other area of the park, left-back is always going to be a problem position until one of these players improves vastly. The Rangers manager can either go for Barisic, who is good going forward but poor in defence, or Flanagan, who can defend but offers next to nothing in an attacking sense. Halliday, meanwhile, is somewhere in between the two.

The fact of the matter is that of these three players, at present, none are good enough for a team with title pretensions. Both Barisic and Flanagan, while they offer Gerrard a viable alternative to the other, are fundamentally flawed.

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The two players' heat maps from the current season demonstrate this even further. Flanagan rarely ventures beyond the half-way line, contributing almost nothing in attack, while Barisic is spending too much time in a position where you would expect to see a left winger.

Of course, Gerrard's tactics play their part here. When playing in a 4-3-2-1, there is a heavy onus on the full-backs getting forward to provide width to the attack. James Tavernier, on the right flank, does a fine job of this, although the Rangers captian does admittedly get caught too far forward on occasion.

When Flanagan starts, he simply does not venture forward and as a result Gerrard's side becomes lopsided. We saw as much during the recent Old Firm game at Ibrox and it resulted in Rangers launching hopeful balls forward as their was no viable alternative. Barisic can provide such an outlet, but he has a habit of being caught out of position and even when he gets back, is not a reliable ball-winner.

Because of this, we are likely to see Flanagan given the nod in fixtures where Rangers could be under the cosh for spells of the game - in Europe or against Celtic, for example - but his inability to contribute in an attacking sense will blunt Gerrard's side to an extent. Barisic is more suited to games against lesser oppostion, yet remains vulnerable. Until we see a marked improvement from one of these players, Gerrard will have a selection headache and the Rangers boss may be forced to dip into the transfer market once it reopens in January. Time will tell if Barisic will eventually come good at Ibrox, but there can be little doubt that time is running out for the Croatian to finally fulfil his potential at the club.