And Edinburgh's bid to not only chalk up an aggregate head-start on neighbours Glasgow for the trophy, but to also finish 2007 as Scotland's top side has been boosted by the return of Callam, Kerr and Southwell.
Back rower Callam missed Edinburgh's heroic victory over Leinster in the Heineken Cup because of a neck injury, but has been handed the No8 shirt for the visit of Glasgow.
Prop Kerr also missed the win against Leinster with turf toe and reclaims the tighthead spot while full-back Hugo Southwell is named amongst the replacements after being ruled out with an ankle injury for three games.
In an unchanged back line, Ben Cairns, who scored a try against Leinster, retains the number 15 shirt and he revealed he is fully focused on helping Edinburgh win; even though he made his professional debut while on loan at Glasgow almost two years ago.
The versatile back claims the short time he spent at Glasgow in January 2006 was beneficial to his overall development, but he is adamant he is very much Edinburgh through and through.
Cairns said: "There are no mixed emotions about his game at all; I was brought up in Edinburgh and I'm Edinburgh through and through.
"But it just so happened that Glasgow needed a centre and asked for me to go through which was good because at the time I needed the experience.
"It was slightly weird playing for Glasgow instead of Edinburgh, but all the boys were brilliant and Sean (Lineen) took me in training and gave me a game. I ended up getting on fairly early when I came on after 20 minutes.
"It was a good experience and I learnt a lot from my short time at Glasgow.
"Nevertheless I'm now playing for my hometown team and will be doing everything I can to beat them on Friday 28 December."
Edinburgh Rugby Club squad to play Glasgow at Murrayfield (Friday 28 December, kick-off 7.30pm)
15 Ben Cairns
14 Andrew Turnbull
13 Nick De Luca
12 John Houston
11 Simon Webster
10 Phil Godman
9 Mike Blair
1 Allan Jacobsen
2 Ross Ford
3 Gavin Kerr
4 Matt Mustchin
5 Ben Gissing
6 Allister Hogg (captain)
7 Ross Rennie
8 David Callam
Substitutes: Andrew Kelly, Augusto Allori, Craig Hamilton, Roland Reid, Ben Meyer, David Blair, Hugo Southwell.
63x46.png){kind=logo}