The Argentine midfielder was a key member of the R's side that won the Championship title last term and Ferdinand has been impressed by the way he has adapted to life in the top flight.
"All the lads that were here last season have adjusted to life in the Premier League well, but Ale - for me - has gone from strength to strength, game after game," Ferdinand told the club's official website.
"I knew what Tarbs (Adel Taarabt) and a few others had before I came to the club, but Ale has really surprised me.
"He's got a wand of a left foot, but not only that, he knows when to play short, when to play long, when to dribble, when not to.
"He's got the ability to be a flair player one minute and then put the graft in the next.
"He loves a challenge and works hard for the team at the same time - it's brilliant if you've got team-mates like that alongside you."