Rangers and Celtic did not take a knee ahead of the Old Firm derby on Sunday, following allegations of racism against midfielder Glen Kamara during Thursday's Europa League defeat against Slavia Prague.
UEFA said on Friday it was investigating incidents in Rangers' clash with Slavia Prague after Kamara complained of being racially abused by a visiting player.
Rangers boss Steven Gerrard confirmed their stance in a prematch interview.
"We won't take the knee," he said. "I spoke to both my captains [on Saturday] and they've made a collective decision that they're going to stand and they're going to stand together side by side and we'll support that and follow suit as a staff as well.