It has been enough for Irish fans to cast their eyes ahead to home games against big guns France and England and forget that Ireland go to Edinburgh having been soundly beaten there in 2001.
On top of that the Scots are an in-form side themselves, and Horgan said: "It's far too early to be talking about playing England and France.
"We're going to concentrate very much on the Scotland game. We'd be very foolhardy to look past that."
Ireland have not won at Murrayfield for 18 years, and Horgan added: "Recent results there haven't been too favourable for us, so we'll just see how things go on Sunday and go on from there.
"The Scots scored an historic victory over South Africa at Murrayfield in the autumn. I'm sure they rated it as highly as we valued our win over Australia.
"Their win can't be forgotten, because there are not too many bad teams who beat South Africa."