Callam insists he relishes the big games as he prepares to return to the Edinburgh starting line-up, and he is eager for more international action.

The 24-year-old returned from the World Cup needing knee surgery but is ready to start matches again, having tested his fitness in an appearance off the bench in the defeat to Toulouse last weekend.

Saturdays opponents in the European Cup will be Leicester Tigers, last seasons Premiership champions, and Callam is a confirmed starter for the Welford Road clash.

Callam was one of the Scotland players who came into the team at Murrayfield to face New Zealand during the World Cup, when Frank Hadden named a weakened team to preserve his first-choice side for their crucial clash with Italy.

He is determined to mount a challenge to Simon Taylor for the back-row role ahead of this seasons RBS 6 Nations Championship.

Callam said: Personally the World Cup was a great experience, but obviously it was disappointing that I didnt get any more game time.

I want to be pushing for Scotland for the Six Nations and the summer tour, but that starts here at Edinburgh with the game-time. Im looking to improve every week both in training and in games.

Leicester should be formidable opposition for Edinburgh, but Callam knows all about facing the best teams.

He said: It is interesting that the only games Ive played this season have been against South Africa, New Zealand and Toulouse.

So the calibre of opposition Ive come up against has been very high and that will be no different against Leicester. It is just another challenge for myself as an individual and Edinburgh as a team.

Edinburgh, who experienced a turbulent summer with key players leaving and the club changing hands, have not won since September.

But Callam is convinced they are a club heading in the right direction.