Given this 800m, as a tune-up for Monaco, is serving the purpose that most 800m races have served for Centro--a chance to fine-tune 1500m speed--I would not expect too much. But you never know. If he can get close to his 1:45.8 PR or exceed it, I would deem the race a success, especially given the strength work he's been doing.
Rudisha is in the race, so you know what that means. I would anticipate Centro to race in roughly the same style Kiprop ran the 800m this past weekend, starting out back, getting dragged to a fast 200-300m, then slowly working up from there, if he can. But my guess is that if he wants break that PR, he needs to hit 400m in 51.0 at the least.