Since the sax will not be bolted down there will be constant but minor changes in the phase as the player performs (movements due to breathing, finger changes, swaying as it's played, etc.).
Trying flipping the phase on one of the mics and go with whatever sounds the best.
Personally I never had a phase problem recording sax but I never used 2 close mics.
Usually I used a combination of a dynamic and a large diaphragm condenser.
I usually had the dynamic 2" to 6" from the sax aimed down the bell (favorite was an RE20) and the other a foot to several feet away (usually something like a 414, C12a or u47) - distance depending on the musician and the room.
These were mixed live to one track (2" tape era).
Exactly where the condenser was aimed depended on the instrument - with clicky pads or noisy keys aiming directly at the body of the sax could capture a lot of noises distracting to the performance.