The forward received a late call-up to Craig Levein's squad this week after Robert Snodgrass and Jordan Rhodes were ruled out injured.
And Commons is now hoping to be involved against Wales in the massive Group A clash at Cardiff City Stadium this evening.
The 29-year-old reckons playing for the Hoops in Europe will help him in the showdown with Chris Coleman's team.
He said: "We all want to reach the World Cup finals. It is a huge thing playing against the best players in Europe at club level in the Champions League.
"I am playing with a lot of confidence and that has been reflected in the results we have had at the club, especially in the Champions League.
"Our whole pre-season was set up to qualify for the group stage and I think our results and performances so far have given the whole of Scottish football a boost.
"A lot of the players in the Scotland squad play in England against some of the best players in the world, but, as a country, we all want to compete against the best nations at the World Cup finals.
"This one we desperately want to be involved in as it's being played in one of the real homes of football, Brazil."
Commons added: "The next two games are really important, but it was always going to be a group where countries take points off each other.
"I hope to be given the opportunity to contribute to two huge games. We need to win against Wales first and then we can see about Belgium after that.
"After two draws it is important to get a win and the way the group is set up, that could put us right into contention.
"I have been keeping an eye on the squad during the time I have been out and the important thing was to keep playing as well as I could and I knew the opportunity would come.
"It's great to be back again. I am now just looking to grab it with both hands."
