The Rossoneri host the Scottish champions at the San Siro in their opening Champions League group stage fixture on Wednesday night and Dutchman Emanuelson is well aware of his fellow countryman Boerrigter who came through the Ajax youth academy at the same time.
"There have been a lot of changes in the Celtic team since last season when they did well in the Champions League," Emanuelson said.
"But, of course, I know players such as Samaras, who had a long time playing well in Holland with Heerenveen.
"I played alongside Derk in the Ajax youth team. When he made it into the first team there it was at the same time I was leaving Amsterdam.
"Derk is a very good player and his pace is incredible. He's very fast and also has a good cross at the end of the runs.
"If he plays against us he is a player to be watched. The Champions League and Celtic is a chance for Derk to grow as a player.
"He started well at Ajax but he got injured and then things began to become a little bit difficult for him.
"I'm happy for him that he now has the chance to be playing for a big team in the Champions League."