The result has been West Ham move up to seventh place in the Premier League table during the opening few weeks of the season, and McDonald believes that the strength in depth bodes well for the remainder of the campaign.
"I think this is our best squad. We have been here three years and in the third year your team should be a lot stronger and I think that is proving to be right at the moment," he told the Newham Recorder.
"We have great competition for places. Whoever the manager picks, it is going to be a good team and if a player gets in, he will keep his place if he is playing well."
West Ham return to Premier League action on Saturday when they travel to struggling Burnley.