Dublin Dilema !

Hi Gang,
I need your advice.

Just before running Glasgow I was diagnosed as having 'early degenerative failure in my right knee. This was after some weeks of discomfort while running to and from work - the knee felt like it was going to burst!!

I ran Glasgow quite happly, in fact it was my fastest Glasgow run in spite of the weather. I also ran Lake Vrynwy and was within 45 secs of my PB set 6 years ago.
I have not been running for the last few weeks, tried to do 14 miles last sunday and although the knee was fine, the rest of me was knackered.
Did 15 today, and then totally ran out of energy.

Problem is, I am due to Run dublin next monday - do I run or not ???

Similar predicament, last few weeks had a niggling injury which is now better, but then got a cold. Tried a run at the weekend managed 13 but felt heavy, so followed that up with an hour on the X-trainer.
Having said that I'm still going to run Dublin, but I may have to re-assess the pace, was hoping for around 8 1/2 minute miles for the 1st 20 and then holding on for what ever I can. This may now change to nearer 9 1/4.
My advice would be forget all about finishing times etc and just go and enjoy it.