Allardyce is having an angioplasty, a procedure to widen one of his coronary arteries, on Friday.
He will also miss matches against Fulham and Stoke and McDonald said: "Hopefully we have put a bit of a smile on his face and taken a little bit of stress away from him.
"I would like to think it will give him a chance to recover knowing his team has done well.
"Sam is a person who looks after himself. He is always having check-ups and making sure he is in good health.
"Luckily they have found it out very quickly. I am told it is routine operation, so he should be back fighting fit very soon.
"I would imagine he would be okay next week for match against Chelsea.
"I spoke to him before the game - and he spoke to the players yesterday. They all knew what they had to do. We all have to take responsibility as we are professionals."