John Souttar winced in pain as he struggled through his Rangers debut at Livingston and it was nothing to do with the plastic pitch.

The nagging doubts about his fitness that had plagued his thoughts over the summer were now coming into sharp focus. This was more than self-doubt. Once again, something was wrong.

Even in Souttar's darkest moments, he wouldn't have expected the issue would keep him out for the best part of the season, but that's what it took, another extended lay off in a career stymied by them.

But if there's one thing about this player we already know, it's that he's made of stern stuff. You don't keep coming back for more unless you have the heart for battle. And when you watch him perform, you know he's not short on that front.

Souttar plays with his heart on his sleeve, wholehearted and committed, never backing down. You always know he's on the pitch because of that defender's x-factor; personality. His own words from a few weeks ago illustrate the point: "I think you have to be mentally strong. You have to have an end goal, focus on coming back, focus on being the best you can and focus on playing for Rangers. That's what I signed to do."

Such strong talk is emblematic of the man and in stark contrast to his competition, the mild-mannered Ben Davies. There is little doubt the Englishman is a talented, sophisticated defender but most are now in agreement he's in the wrong movie at Ibrox. And that's exactly because he lacks that simple personality factor. Sadly for him, if you're a defender at a club whose history is littered with those capable of decisive performances in your position, you don't get far without it.

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Richard Gough, Lorenzo Amoruso, David Weir - as defenders, they all had that stardust and were leaders of men. Each is better than Souttar of course, and to name them is not to suggest the 26-year-old is in the same league, but rather to simply emphasise how personality and performance is linked. And you can't show that anywhere better than in the Old Firm derby theatre.

Souttar's first taste of the fixture was promising until the fateful moment he mismeasured a back pass to Allan McGregor. The 41-year-old keeper needs accurate balls back to him and this one was 15 percent off the mark. 10 years ago, McGregor would have launched it into the stands, turned and excoriated Souttar with that vicious tongue he's famous for to remind him about standards. But it's not 2013, he didn't get there and Jota rolled the ball into an empty net.

That's a big hurdle to overcome, a real blow to any player. Some have crumbled under the scrutiny that comes from a Celtic calamity. So to see Souttar flying through the air to nod home Rangers' second at Ibrox today, out-fighting Carl Starfet to the ball, the word that came to mind was simply 'personality'. It was the perfect answer to criticism.

On the strength of his performances when utilised, not least this afternoon, Souttar has surely earned his place as part of Michael Beale's summer rebuild. The manager was known to be an admirer on his last spell at the club and was delighted to have the defender at his disposal when arriving in November. You suspect there will be no desire on either side to see this burgeoning relationship come to an end.

While today's stroll in the sun will have been a last dance for some, you sense Souttar will enjoy a few more strutting his stuff at Ibrox yet.