"It will be good to see so many old friends again," said McCall, who lifted European club rugby's most coveted trophy with Ulster's current Director of Rugby David Humphreys against Colomiers at Lansdowne Road in 1999. He then went on to coach Ulster between 2004 and 2007.
"Obviously I still keep in touch with the Ulster management boys at Ravenhill so it will be good to have some banter in the build-up to the quarter-finals," he said.
"They are having a phenomenal season. Along with Clermont, they have been the form team in Europe this season."
But not even a first tournament win on French soil over Castres Olympique could stop forcing Ulster onto the road in the knock-out stages, McCall adding: "That was a great result, particularly when you consider the six or seven key players - massive players - they were without.
"But they've got this strength in depth which they've never had before, so they can cope with injuries. And as we understand it, almost all of those players will be back by the time they come to play us.
"It's a really hard tie for us. It's going to be difficult. I'm just so grateful that we got a home draw."