The Real Madrid team-mates will be the two biggest stars on show for Sunday's Group E game in Cardiff.
Croatia lead the pool on 13 points with Wales six back in fourth spot, although Ryan Giggs' side have a game in hand.
Wales drew away to Slovakia on Thursday, Bale sustaining a knee injury, but he is expected to be fit to face Croatia.
The forward is looking forward to testing himself against Ballon d'Or winner Modric, Croatia having won the reverse game 2-1 in June.
"Whenever we have played we've always lost by one goal and it’s always been quite a tight game," Bale told reporters.
"We know what a great team they are, they had a great World Cup and they have shown year after year how good they actually are.
"We know it is going to be very tough, but I think being at home gives us a little bit more of an advantage and we know the Welsh crowd will be behind us.
"We've played together for a long time in Tottenham and Real Madrid so we know each other quite well. It would be nice to get one over on him finally because they have beaten us a few times in the past."
Bale is one booking away from missing a qualifier through suspension, which he accepts will be on his mind against Croatia.
"I can't make too many silly tackles or anything, I have to be mindful of that," Bale said. "I don't want to miss any games for Wales and especially at the crunch time of the group.
"I guess I have to be clever with what I'm doing but maybe I have to expect that someone is going to wind me up to get me suspended."