Rangers have won their last 14 league games on the trot and have a 19-point lead at the top of the league table, albeit playing three games fewer than their Glasgow rivals Celtic, who are second in the standings.
The Gers beat Celtic in the Old Firm derby last weekend and many now feel the race for the title is effectively over.
Rangers have not suffered many hiccups in their first 22 league games, winning 20 of them, but McManus believes they will drop points at Pittodrie on Sunday.
The Gers beat Aberdeen 1-0 on the opening day of the season at Pittodrie and hammered them 4-0 at Ibrox in November.
But McManus stressed that the Dons are in a better state at present and believes that they could get a point against Rangers on Sunday.
The former striker said on PLZ Soccer: “I think Aberdeen have got a stronger squad now than the previous couple of games.
“They are on a good run of form and I think they are going to get a draw.
“I am going for two each.”
Aberdeen are unbeaten in their last five games and Rangers’ rivals Celtic are looking to the Dons for a favour.