I’d lean towards the second option- rest but I’d do a warm-up in the AM of the Fri race day. Thsi will get the blood going and make it a lot easier to warm up for the real thing in the afternoon. This is usually a good plan whenever you don’t have heats. You can do the warm up either in the house with limited sets of push-ups, sit-ups etc or just outside. Don’t bother going to the track or anything major like that!