The two sides are separated by just six points at the top of the Scottish Premiership.
Gary Mackay-Steven is adamant that Celtic need to take Aberdeen seriously as he insisted that the Dons will be ready to take advantage of the title race if the Hoops slip up, according to the Evening Times.
Ronny Deila's men are currently six points clear at the top of the Premiership table - and have a goal difference that their nearest challengers will do amazingly well to get close to this season - but Mackay-Steven urged his team not to let their standards slip as Aberdeen could seize the initiative if they leave the door slightly open.
"Aberdeen are not far off us. They are playing well and winning games, so it is definitely a title race," he told the Evening Times.
"Last season they had a challenge for quite a while. Obviously, we finished well ahead of them in the last few weeks of the season, but Aberdeen are sticking by us this time. They are on our heels, playing well, and we need to take them seriously.
"It can only benefit us. We need to be at the top of our game, we can't rest on our laurels and just think we will win the league easily. It's certainly far from that. We need to be at the races every single week."
Derek McInnes' side struck a huge psychological blow when they claimed the three points when the two teams met at the start of the month. And while that result, as well as the form they had enjoyed before it - the victory over the Bhoys was the penultimate game of their 12 match unbeaten run in the league - suggested that they were going to push Celtic all the way, the momentum appears to have now switched back.
While Deila's men bounced back from the defeat to the Dons by winning their next three games in all competitions - including two in the league - Aberdeen missed a golden opportunity to apply some more pressure as they lost to Inverness.
And with Celtic's next game being played a day earlier than their title rivals' clash with St Johnstone, the champions will have the opportunity to temporarily go nine points clear and take a sizeable step towards the league crown.