Diego Simeone's men extended their 100 per cent start to the season to seven games with a 1-0 win at city rivals Real last Saturday, then pulled off an impressive 2-1 Champions League win in Porto in Tuesday.
But although Atletico will start as overwhelming favourites against a Celta side without a win in five, Koke knows they could be in for a shock if they try to take anything for granted.
He told a news conference: "Celta is a very difficult game because it is the first time we have played at midday and we are going into it off the back of two very demanding games.
"I'm happy that we've done a great job on a game as complicated as Madrid, but we'll keep our feet on the ground. We must look to keep doing the same things because we are doing them well."
Simeone has doubts over Raul Garcia, who limped off against Porto with an ankle injury, but Mario Suarez is available after a knee sprain and Diego Costa returns from suspension.
Meanwhile Celta boss Luis Enrique called a crisis meeting this week after his side slumped to their second consecutive defeat last Sunday 1-0 at home to Elche.
The defeat plunged Celta to 15th in the table with just six points from their seven Primera Liga games so far this season.
Defender Andreu Fontas said: "Atletico are a great team and we will have to go there to do our job and take it very seriously. We have to be good defensively if we are going to stand any chance."