Rules: Mid-tournament substitution

Some of you may remember the irritation/confusion in the Manchester/ENG vs. Erlangen-Nuremberg/GER semi-finals 2009. We have asked James Pearson, the Manchester team captain in 2009, to provide us a rule for our tournament booklet. He suggests:

The team which wishes to make a 'mid-tournament' substitution must consult with both the opposition and the tournament committee. The decision to allow a replacement is entirely at the committee's discretion and subject to approval from the oposing team captain.

No objections, neither from England, nor Austria and Germany. So it's an official rule as of now.