Mackay-Steven, who moved to the Hoops from United in the January transfer window, has been impressed with the personality of his new Celtic teammate.
“He has the kind of character that can deal with pressure situations and being at a massive club,” the 24-year-old Scotland international winger told The Scottish Sun.
“He’s quite loud and annoying, he’s made himself heard. At first he was pleasant and quiet but he’s come out his shell now.
“He’s cracking jokes and speaking Turkish and being himself. You need to keep your eye on him because he’s a big character on and off the field.”
Good signing for Celtic?
Ciftci is one of the best strikers in the Scottish Premiership and has been in brilliant form for the past two seasons.
In the 2013-14 campaign, the former Turkey Under-19 international scored 17 goals and in 2014-15 he found the target 16 times.
Ciftci is a very good striker who can score different kinds of goals and also brings his teammates into play.