The Baggies have embarked on an unbeaten run of four matches in the Premier League following the Frenchman's arrival from Marseille on transfer deadline day.
Amalfitano has scored two goals during that time, including a superb solo effort in a 2-1 win over Manchester United at Old Trafford.
"He is some player," McAuley told the club's official website. "I don't know who plays on the right of midfield for Marseille but he must be decent.
"He mixes it up and he does a great job for us without the ball as well, which some people might not see but we certainly do as players."
West Brom return to Premier League action on October 19 when they travel to Stoke City.