But theyve isolated for 7 days already have they not?
I don't think they have yet. If Prenetics have the capacity to do two batches of tests per week, with a 48 hour turnaround time and 7 days isolation then the schedule should look something like this:
Day 1 - Test 1
Day 3 - Test 1 results (isolation period starts for any positive cases)
Day 4 - Test 2 (players in isolation from test 1 not tested)
Day 6 - Test 2 results (isolation period starts for any new positive cases)
Day 8 - Test 3 (players in isolation from test 1 + 2 not tested)
Day 10 - Test 3 results (isolation period starts for any new positive cases)
Day 11 - Test 4 (players who tested positive on Test 1 are out of isolation and should be tested again - Test 2 positives still in isolation)
Day 13 - Test 4 results ((isolation period starts for any new positive cases)
Day 15 - Test 5 (players who tested positive on Test 1+2 are out of isolation and should be tested again - Test 3+4 positives still in isolation)
They are trying to improve on the 48 hour turnaround - in fact I think yesterdays results may have been from tests on Friday. No doubt test days will slip or have to be adjusted for various reasons and teams might not all test on the same day but you can see how relatively quickly it could build up IF there are lots of positive cases.
But I do think 8 positives is not a huge amount in the first week and bodes well for the chances of the PL actually getting started again. That is on the proviso that players and staff make quick and full recoveries from any symptoms.