5k Scheduled on Week 5 Day 6

[Guest Jangles]

Hi. I'm following the 26.2 program and am supposed to do a 90 minute (3:2 interval) on Saturday morning but am scheduled to do a 5k (my first - bucket list) that evening. 

I also have a 10k three weeks after that and want to keep on track to be ready for that (I'm very slow and it takes me 55 minutes on a 3:2 interval workout to hit my 5k). 

I'm wondering if I should do the 90 min workout in the morning and the 5k in the evening or if I should break my 90 minutes up to cover a morning and am evening run. Any suggestions?

 

Thanks.