THOMAS MULLER has blasted out Champions League warning to Celtic as he promised five-goal Bayern Munich will be even better on Wednesday.
The skipper insisted the Bundesliga giants are back in business under comeback veteran bosss Jupp Heynckes after hammering Frieburg 5-0 yesterday.
Muller claimed the opener as his team strolled to victory in front of 75,000 at the Allianz Arena and he admitted it was close to perfection.
He said: ”We wanted to show a great performance in front of our fans. There is no perfect game in football, but this was close.
“The coach change is important, but as players we also have to improve.
“It was very good, but we keep our feet on the ground and prepare for the game against Celtic.
“We did not reinvent the football, but the team did well with the coach.”
Heynckes admitted he was thrilled to get off to a flier after replacing the departed Carlo Ancelotti.
But he insisted his side will need to sharpen up in defence against the Celts.
He added: “This is a positive start for us after a difficult few weeks.
“A manager must be at one with his players and I want to work with the team so we can keep improving.
“We have made a good game over long periods, but we have also allowed Freiburg three chances in the first-half.
“That must not happen to us. We must be safer, more compact and cannot lose the ball when we are all going forward.
“You can build on the win, but it’s not all wonderful. We still have a lot of work to do – we can improve a lot.”