Noble's place in the West Ham line-up is generally considered a given, but the strength in their midfield ranks has meant that he is not longer guaranteed to be part of Sam Allardyce's starting team.
"Mark Noble has been a staple of the team for a number of years, but Alex Song has come in. So we've had to make a decision about having one or two sitting midfielders," McDonald said to the club's official site.
"Cheikhou Kouyate has come in and also done very well. We've got Kevin [Nolan] coming back and Stewart [Downing] playing in a new role. So we've got lots and lots of options."
Despite McDonald's words it is still expected that Noble will start at the weekend against Burnley, after recovering from injury.
There were concerns that the English midfielder could have been sidelined after picking up a knock in their last fixture before the international break, but he has recovered quickly.
That is a boost for Allardyce's men who have made a very positive start to the season.
With their new attacking brand of football, the side have climbed into the top half of the table and they will be hoping to stay there for the foreseeable future.
McDonald is certainly optimistic that they can and he commented on the role that the new signings have had in sparking this improvement.
"Last season we scored a lot of goals from open play and then injuries slowed us down. In the end we didn't get as many points as we should have done," he said.
"I think the new signings have helped bring a freshness in. They can play the ball well, perhaps better than we've had before. We're creating more chances than we've done before, we're getting more of the ball and sticking the chances away more regularly."