Lions head coach McGeechan has made it clear that he will be keeping an eye on more than just his own club's progress as begins the process of assessing the form of potential Lions from across the four Home Unions.
"The Heineken Cup will be the first real challenge for the players," said McGeechan, who will be attempted to lead London Wasps to their third top-European crown.
"You have to think differently in this tournament and I'll be watching all the games with great interest.
"The final will be another big occasion and a full Murrayfield would be quite special. With the new seeding system it's a very difficult tournament to call."
Heineken Cup Round One fixtures
Friday October 10
Munster vs Montauban
Perpignan vs Treviso
Saturday October 11
Calvisano vs Cardiff Blues
Clermont Auvergne vs Sale Sharks
Edinburgh vs Leinster
Gloucester vs Biarritz
Newport-Gwent Dragons vs Glasgow
Scarlets vs Harlequins
Ulster vs Stade Francais
Sunday October 12
Leicester vs Ospreys
Toulouse vs Bath
Wasps vs Castres