Kris Commons believes his sizzling form for Celtic this season has been aided and abetted by his retirement from the Scotland set-up.

After 12 caps and two goals in dark blue, the 30-year-old attacking midfielder called time on his international career last May which freed him up from the dying embers of a doomed 2014 World Cup qualifying campaign.

Commons has thrived without the "distraction" of the national side, scoring 16 goals on the way to winning the Scottish Professional Football League player of the month award for December, which he picked up at the club's Lennoxtown training complex on Thursday.

Ahead of the Scottish Premiership clash with Motherwell at Parkhead on Saturday, the former Nottingham Forest and Derby player spoke about the benefits of focusing solely on club football.

He said: "I have been out of it (Scotland set-up) for the best part of six months and form-wise and goal-scoring form-wise, I haven't played as good and probably never scored as many goals at club level.

"Without that distraction, it has certainly helped me.

"When your sole purpose is concentrating on Celtic then you tend to play your best football.

"When you have other directions and other aspects of your game you have to concentrate on, and travelling, it does take it out of you.

"I am not 22, 23 any more, where it doesn't really effect me.

"I am 30 years old now and I am in the position where I can solely concentrate on Celtic and get the best not only for myself, but for the team as well.

"I would never say never (to returning) but at this moment in time - I have a four-year-old, a three-year-old and a one-year-old - and when I am not playing with Celtic and playing football it is about spending as much time as I can with my kids.

"Last season I scored one goal in the whole campaign so it is about keeping my feet on the ground and accepting that sometimes I won't get the chances in games that I deserve.

"But hopefully they will keep coming my way and I will keep putting them in the back of the net."

Commons will get some added competition in the shape of Stefan Johansen, the 23-year-old midfielder who signed this week from Norwegian champions Stromgodset.

He said: "If this new signing is very good, you need to step up, train harder, work harder, and score more goals.

"He is a very good addition to the squad and healthy competition is good."

Manager Neil Lennon welcomed his latest signing to his squad although he is hoping for even more new faces in before the transfer window closes.

He said: "He is a good footballer. We have him watched on a couple of occasions and the reports are good.

"He trained today, he is well-balanced, with a good range of passing and will add quality to our midfield".

The Northern Irishman revealed there has been little progress with regards his bid to keep Georgios Samaras and Joe Ledley, both of whom are out of contract at the end of the season.

The former Hoops skipper said: "We don't know were we are with Georgios at the minute, we still haven't a definitive answer either way.

"The signs with Joe are more positive but again, we have no confirmation of that.

"There is no deadlines but the longer it drags on the more speculation there will be about the two of them and obviously we can do without that at the minute."