Title-winning teams require players who can swing matches and change outcomes, even when their team isn’t in the ascendency.

For Rangers, no recent game has better epitomised this in an attacking sense than a recent 3-2 defeat at Parkhead. Having fashioned a slightly higher xG than Celtic on the day (0.87 to 0.6xG) Michael Beale’s side failed to capitalise on the periods of dominance they enjoyed. In a game decided by fine margins, it was their opponents who capitalised on half chances.

Alfredo Morelos had a 0.16 and 0.17xG chance at the start of the second half that he could not convert, whereas Kyogo put the hosts ahead with his 0.12xG opportunity.

At the other end, Allan McGregor has not enjoyed one of his finer campaigns. The decision to not invest in the goalkeeping position last summer looks to have been the wrong one when casting judgement over the numbers.

At both ends of the park this season Rangers have suffered from a lack of game-winning performances. To quote Beale, “Ultimately it comes down to the boxes. You’d like to be dominant in between but big games are won in the two penalty boxes. The games are always tight and generally won or lost in moments.”

Last season, McGregor was the subject of more obvious mistakes leading to dropped points. Think of a late flap in a 3-3 draw with Ross County, or his costly second-half performance in a 2-2 draw with Motherwell. Earlier in the season, failure to deal with a Hearts corner at Ibrox spurned three points.

With that said, although this season has perhaps featured fewer obvious errors, the stats show that rather than making a positive contribution over the course of the season, both of Rangers’ keepers have cost goals.

Domestically, the Ibrox side have conceded 34 goals from an xG of just 20.74 after 33 games.

What does this mean? Based on the quality of chances opponents have fashioned, they’ve significantly overperformed their goal return.

Things don’t get any brighter when you look at the Post-Shot xG. Remember, while xG charts the likelihood of a chance turning into a goal, PSxG re-evaluates that probability once the effort has been taken. Considering the quality, placement and velocity of the shot, as well as the positioning of defenders and goalkeepers.

What does this show? The quality of opponent’s efforts has not merited this huge overperformance. For example, if the PSxG was closer to 34 it would suggest that either goalkeeper could’ve done little to prevent those goals conceded, even though the initial chance rating was relatively low.

READ MORE: Rangers' new formation: Why Michael Beale's opting for box midfield

Another statistic that can provide further detail is Goals Saved Above Average, defined as: “How many goals did the keeper save/concede versus expectation (post-shot xG faced)? This is representative of how many goals the goalkeeper's saves prevented within a season.”

Over the course of the campaign, McGregor’s GSAA number stands at an alarming -8.26, a stark contrast to the 3.26 goals saved above average in 2020/21.

Last season, despite those errors previously highlighted, McGregor’s 0.35 total shows his contribution came in at par. Although he cost points, he also gained them to compensate for errors.

Having just hit 500 appearances for the club McGregor is a Rangers legend by every metric but there’s no denying the reality that a new No.1 is required this summer.

Jack Butland is the nailed-on favourite to become McGregor’s successor, with a deal close to being struck between the two parties.

The 30-year-old, currently on loan at Manchester United from Crystal Palace, is available on a free transfer this summer and on the surface of things, it’s a deal that makes sense.

Having not been a No.1 for numerous seasons, Butland needs a move to change the narrative that’s clouded his career in recent seasons. With nine England caps to his name, the former Stoke City keeper hasn’t reached the heights many hoped it would.

Having become his country’s youngest-ever goalkeeper at 19, Butland was a key performer for Stoke in the Premier League and made the 2018 England World Cup squad. The Potters’ relegation from the top flight coincides with the keeper’s own trajectory since that summer.

The last time Butland made more than 10 league appearances came in Stoke’s 2019/20 Championship season. A move to Palace three seasons ago never translated into regular football, hence the six-month loan deal at Old Trafford in January.

There are shades of the Todd Cantwell transfer. Butland is also a player with undoubted quality that needs a new challenge.

Given the amount of change required in the Ibrox playing staff, there is a reality to each deal Beale will strike.

A free transfer here will save money for another key acquisition there. Having made no secret of the fact that he’s driving recruitment in the absence of a Sporting Director, Beale has repeatedly spoken of meeting potential targets.

“If the window goes how I plan it to go, then you'll be able to trace a lot of the players back to some that maybe I've worked with or you'll be able to see the links, they'll be clear. It's important that we recruit strongly and we recruit the right type of people as well,” the manager said recently during a press conference.

“Do we always get our first choices? No, because I’d like to go and buy Mason Mount from Chelsea because I worked with him and I like him,” Beale added on another occasion, addressing the reality of recruitment at Ibrox.

“We always have to take an element of risk. Sometimes we get a broken child, sometimes we get one before he has flourished and we have to help them flourish, whether that is Calvin Bassey, Nathan Patterson or Todd Cantwell from Norwich who was going great guns and then had a few changes of manager.”

A move for Butland has that risk attached. The lack of substantial game time in recent seasons could be a red flag for some.

There is also big potential reward in securing a deal for a keeper with talent and ability that always seemed destined for higher heights than Scotland.

To win things Rangers require a difference-maker in goals. Could Butland be the man to fill that void?