KRIS Commons made an immediate impact when he signed for Celtic from Derby County for just £300,000 four years ago.

The Scotland internationalist netted a stunning long-range effort after just six minutes of his debut against Aberdeen in the League Cup semi-final at Hampden in 2011.

It was a taste of what was to come from the skilful forward; he has pretty much carried on in that vein, the occasional dip in form aside, since that day.

He was certainly the difference between his side and Ross County at the Global Energy Stadium in an SPFL Premiership match at the weekend.

The 31-year-old was comfortably the most impressive player on the park up in the Highlands and scored the only goal of the game early in the second half.

His deflected strike ultimately ensured the Parkhead club, who have a game in hand, moved three points clear of Aberdeen at the top of the league table.

What, you wonder, would Celtic manager Ronny Deila give for Commons to make the same contribution as he did against Aberdeen or Ross County this Sunday?

The hotly-anticipated League Cup semi-final with Rangers at the National Stadium is the biggest match of the Norwegian's reign so far.

Bigger even than the Champions League qualifiers against Legia Warsaw and NK Maribor back at the start of the 2014/15 campaign.

Financially, victory will not matter as much as in those European ties.

But success will mean more, much, much more, to Hoops supporters. Commons has done exceptionally well against the Ibrox club in the past.

Indeed, he has netted three times in just seven appearances against them.

There is no other individual at Deila's disposal with the ability to raise his game on such a huge occasion, unlock the opposition defence with a moment of magic or bag a crucial goal. So why the Celtic board is continuing to stall over giving the player the two year contract extension he justifiably feels that his service to the Parkhead club merits is mystifying.

If the Scottish champions, whose attendances have decreased this season in the absence of Hearts, Hibs and Rangers from the top flight, are looking to drive down the wage bill it would be understandable.

However, after his heroics at the weekend the former Stoke City, Nottingham Forest and Derby man was at pains to point out that he was not being greedy in his demands.

And surely the loss of such an entertainer, a player who football fans would happily pay their hard-earned money to see, will have a further detrimental affect on gates?

The Celtic hierarchy would give the players and support an enormous lift ahead of the Rangers match by ending the impasse with Commons this week and giving him the contract he is after.

Former Celtic manager Neil Lennon is keen to take the attacking midfielder to Bolton Wanderers and is monitoring his situation.

It would be a huge blow to the Glasgow club to lose him in the coming days. Deila agreed: "It would be a boost to keep Kris. There are two different views just now. But both parties want to solve it.

He will stay until the end of the season whatever happens."

Despite the ongoing uncertainty over Commons' future, Celtic are in a good place entering the League Cup tie after winning their fourth game in succession.

They have netted nine goals and conceded none this month.

Yes, the loss of Charlie Mulgrew for six weeks is a huge blow.

The Scotland man is another player who thrives on the intensity of the game against Rangers and has a proven track record in it.

Yet, their preparation has been far better than that of their opponents whose game with Cowdenbeath was postponed on Saturday - six days after their match with Hearts was abandoned.

Deila is certainly looking forward to the meeting with Kenny McDowall's charges with anticipation and is confident his side is well placed to win the match and progress to the final of the competition. "I think we are in good place now," he said.

"We know it's a big game for many reasons. But if we perform at our very best then it is very hard to beat us. It's up to us."