Scotland and Gordon Strachan are rapidly approaching the most important fixtures of his reign as national team manager to date.

The matches against Slovakia and Slovenia over the next seven days will determine whether his guidance of the Tartan Army so far is seen as a success or a lamentable failure in the eyes of many. The stakes are so high that a negative result in either match could even spell the end of his job. It's a vital moment, it's D-Day, if you will.

His bid to lead Scotland to the World Cup Qualification Play-Offs hasn't been helped by some injuries to established first-team stars since he made his squad announcement. Scott Brown, Stuart Armstrong and Matt Ritchie were all forced to withdraw after recent matches leaving Strachan with a massive midfield headache.

In response he's turned to a player that has long been tipped for a call-up; Callum McGregor. His form at Celtic over the last 12 months has been remarkable, becoming a key member of a squad that has achieved incredible things domestically and who are well on their way to doing the business in Europe too.

He has long been passed over when it's come to selecting squads for this qualification campaign, but now he's eventually arrived on the international scene, it's actually vital he goes straight into the starting eleven.

Risk and rewards

Giving a player a debut in a match of such importance as could been as something of a massive risk, but with the bravery to make such a call could come great rewards.

The truth is that Celtic's Scottish players are in the best form of their careers right now, with confidence levels as high as can be. If Strachan turns his back on that he is potentially shutting out a performer that has the cutting edge to inspire the much-needed victories.

He's Scotland's best facsimile for the injured Stuart Armstrong, both having performed very similar roles in the Celtic team since Brendan Rodgers arrived at the club. His hard work, a box-to-box graft, is something Scotland could be lacking if he doesn't play. However, that's not even his main strength.

McGregor's ability to drive forward with the ball at his feet and do something special in the final third is arguably even greater than that of Armstrong's, also possessing the kind of finishing skill you would usually associate with a striker. He's scored six goals already this season, almost as many as he scored in the entirety of last term.

When Armstrong made his debut for Scotland in their first fixture over Slovenia, that was seen as a risk too, but Strachan himself ended up calling it perhaps the best debut he has ever seen for the national team. High praise indeed. That's what McGregor can achieve too.

Super sub

Even if Strachan believes the Celtic man is not quite ready to start a match of this important, McGregor could also provide a cameo off the bench that can give the Scotland team something different.

When performing such a role for the Hoops he can either help retain possession and dictate the tempo of a match when they are on the front foot, or as noted, can providing much needed attacking spark when the chips are down.

Whatever happens against Slovenia and Slovakia, the matches are almost guaranteed to be tough encounters for the Scots, that require complete performances across the 90 minutes. Having a player available from the bench who has achieved great things in Scottish football, has progressed well under an elite coach and also has experience of UEFA Champions League football could be a difference maker.

McGregor is not the most fashionable of players. He isn't someone who immediately springs to mind when you consider Brendan Rodgers' Celtic. What he is though is a player who has battled hard for his place in the Celtic squad, then in the Celtic team, and a player who will likely give every bit as much of that application and determination to his national side.

That's the kind of man you want playing for your national team, especially when everything is on the line.