Snedeker is playing in the storied competition for the very first time, but is coming off the back of his biggest win to date at last week's Tour Championship, which secured him a cheque for £10m (£6m) as winner of the FedEx Cup series.
McIlroy said that it is an honour to lead Europe out and vowed to "get blue on the board".
"To be honest they are not the opponents we were expecting," said McIlroy. "We know that their team is so strong all the way through, but it was a little surprise to see a rookie in their first group.
"It is a great honour to lead Europe out in the Ryder Cup. We are going to go out there and get the blue on the board early."
McIlroy is playing in his second Ryder Cup.