McDonald is away on international duty with Australia and is currently preparing for the Asian Cup in Qatar at a training camp in Dubai.
He will keep in touch with his club's fortunes via the internet, but admits it will be difficult not to be able to play his part.
He told Boro's official website: "It's a weird time. Being away from the boys is frustrating - this is the club who pay my wages.
"But FIFA have their rules and if you are told to play for your country, which is a huge honour, you have to go.
"We (Boro) have been competing a lot better in games and dominating at times. There's a belief now that we can go and beat anyone, at home or away."
Source: PA
Source: PA