The Hoops took a major step towards their fourth consecutive Scottish Premiership title when they thrashed Aberdeen 4-0 at Parkhead on Sunday and they could open up a nine-point lead if they defeat St Johnstone in their rearranged home fixture.
Mackay-Steven, who scored in Sunday's win, has settled well into life at the Glasgow giants since his January transfer deadline day move from Dundee United.
And the winger believes the manner of their victory against Aberdeen was a statement of intent to the rest of the league as the Hoops look to close in on a domestic treble
"Can we go unbeaten for the rest of the season? I don't see why not
Aberdeen are second and we've just run out 4-0 winners against them," Mackay-Steven said.
"There is no reason why we can't go on a run now and really get first place nailed down, maintain that lead at the top.
"I think it was a big statement
Every game for Celtic is big but this was a top-of-the-table clash, Aberdeen started the day only three points behind us
So, it's obviously a big statement.
"Aberdeen have been pushing us hard in second place, they've had a great season so far
So, it was important to get the win
And, if we win on Wednesday, that's us nine points clear.
"Aberdeen have been on a great unbeaten run and they're second for a reason - it's been a great season
But we know the quality in the dressing room and we showed that.
"The club is used to winning, there is definitely a winning mentality in the dressing room
Second best is no use at Celtic.
"There is plenty of the season left - we're only in March - but so far, so good,"
The Hoops, who have won eight consecutive matches in the league, could strengthen their grip on the Scottish Premiership trophy if they can complete their third victory of the season against St Johnstone.
Tommy Wright's side have been struggling for form in recent weeks and have won just once in their past six outings in the league
Their last match saw them held to a goalless draw by Kilmarnock, but a shock win in Glasgow would see the Perth side climb into the top six.
Fixtures
Wednesday
Celtic v St Johnstone (1945 GMT)
Source : AFP
Source: AFP