Celtic boss Brendan Rodgers explained holding back Nat Phillips for Sunday's victory over Rangers.
The defender joined Celtic on a six-month loan last week.
However, Rogers says he wasn't ready to take part in the Old Firm showdown.
Speaking to BBC Radio Scotland, Rodgers said: "Nat comes in - and we'd spoken to Liverpool before signing him - and that was one of the considerations that we had, he was going to be ready after the international break.
"We have to respect that, he's a Liverpool player, but after the next couple of weeks he'll be fine to be involved."