It's impressive that whether supporting the MC or his rival is a win-win thing here.
We know it's a zero to hero series, we know it's about sawamura, but him not getting an ace number here is also acceptable thing. There's so many times that this series subliminally give a notion that not being the number one is also an acceptable outcome for a hero. The unused third year, yuki, christ, and the third years from the first act, or many other occasion.
Albeit near impossible, even if sawamura ended up never donning the number one jersey, at the end of this series the journey is what really matter.