The Scottish singer's second disc A Curious Thing and Boyzone's latest offering Brother were both released yesterday.
Reflecting on the chart battle, MacDonald is quoted by the Daily Record as saying: "I don't expect my album will go to the top because Boyzone have already cornered that market.
"It is a bit annoying but it's one of those things. I loved them when I was young but I thought people would get over the whole Boyzone thing."
She continued: "If they get to number one it's fine. I fully expect it to happen. They were getting plenty [of] pre-orders and I don't expect to do well against them. If I did get to the top, I'd be over the moon but I'm just happy that I've got a second album out.
"The last time my album came out, it went to number two and it hung about so long it went to number one six months later. As the record label keep reminding me, it is a 12-month campaign."
Midweek sales figures released today showed that MacDonald was on course to secure third position in the chart. Gorillaz's Plastic Beach and Boyzone's LP were in the top two spots.