Second and third place will guarantee a Europa League spot and Caley Thistle can move level with second-placed Motherwell, and eight points ahead of the chasing pack, if they beat St Johnstone at home.
But Butcher knows the Perth club and Ross County will also fancy their chances, as well as the final club to book their place this weekend.
The Inverness boss, whose side are unbeaten in six games and seeking their third consecutive win, said: "Every club that's gone into the top six will say, 'Right we're there, let's crack on and win as many games as we can and see if we can get that European spot'.
"Every club will be saying that because it is pretty tight. We want to catch Motherwell, we have got to play them up here in the top six.
"We want to maintain this lead that we have got over the other clubs and keep on going and try to secure a European place, as quickly as possible. Yes, we're after it, yes, we want it, and we are doing everything in our power to try and get it."
Saints claimed a last-gasp 1-1 draw with Dundee United on Monday to clinch a top-six spot for the second season in a row.
Boss Steve Lomas now has his sights set on another crack at European football, after facing Turkish outfit Eskisehirspor at the start of this campaign, but acknowledges the task his side face.
He said: "That's the ambition but there are a lot of teams there who also want to get it. You would have to say that Motherwell and Inverness are in the driving seat. The European place is there to play for so, to get on a good run at this crucial stage, will be invaluable."