It is one thing saying you are going to do something, however. And then actually executing it.
For 50 minutes or so, Celtic stuck to Postecoglou's word and stood shoulder to shoulder with Real Madrid. In fact, for large periods they bettered Real Madrid and made them suffer, according to Carlo Ancelotti, in an atmosphere which exploded on the first chime of the Champions League anthem then crackled in the background.
This confidence which the team is brimming with was there to see in the sixth minute. Josip Juranovic threw the ball infield in his own half. Such a move against such opponents usually requires a deep intake of breath as the heart rate increases. But the throw was to Reo Hatate. Luka Modric went to press the Japanese midfielder. Pointless from the Croatian for Hatate had already made his mind up. He met the pass on the volley at an angle, clipping it across the pitch to Jota in space.
Modric could well have stopped, nodded and appreciated a pass which is very much in his wheelhouse. However, the diminutive midfielder didn't have time to think, he had to track Hatate who made a 40+ yard run to support the play on the edge of the box.
No Celtic player epitomised this ballsy and impressive approach to a game of such magnitude against opposition of such calibre as Hatate.
For over 45 minutes he was the best player on the park, dovetailing excellently with the increasingly authoritative Callum McGregor in a midfield two with Matt O’Riley playing closer to Giorgos Giakoumakis. Between them they recovered the ball 19 times.
Everything the 24-year-old did was so smooth. How he took the ball on the half-turn, how he invited pressure and popped off a pass, offered himself for wall passes which can be so vital in moving opponents around. All done with composure. Being surrounded by four Madrid players in his own half never fazed him, nor did facing Modric and Toni Kroos.
“I cannot express with my words what that experience was like,” he said.
“I tried a lot of things, and showed a little of what I can do, and I learned a lot of things from playing against players like that.
“I have to take as much out of this experience as I can and use that to improve as a player.”
This is a player who is starting to motor. He made an instant and indelible impact when he arrived mid-way through the season, most notably in the 3-0 thumping of Rangers. Unsurprisingly, after a full year of football in Japan, straight into action in a new country, adapting to a new culture, his influence waned.
He now appears ready to be an even more dominating force. In his appearances so far he has helped Celtic be so effective and productive down the left-hand side, linking with Greg Taylor and Jota, operating so diligently in those half spaces in the final third to create triangles.
Humble he may be but Hatate demonstrated he was a match for Modric and Kroos.