Though that first-half showing back in December left Rodgers at his angriest, his side still scooped up three points. But they were not gathered the way he wanted them.

There was not the dominance and desire there is now. Nor the hunger and hunting, which is continuing to be led by Maeda.

The Japan international, who Rodgers said just over a week ago was better than anyone at tracking back defenders, was at it once more at McDiarmid.

Six goals up and with 86 minutes on the clock, he charged back and robbed David Keltjens in Celtic’s half. He leaves you exhausted merely watching on.

Fleetingly does the Celtic manager single out a player, but he did so again with Maeda, and indeed the goal he had chalked off, which he believes was the wrong call.

But as his work-rate typifies that of the mentality monsters, Maeda’s own projection in performance aligns with what Rodgers has rallied for.

The one thing missing in Maeda’s game had long been goals. The energy, the enthusiasm and exceptional pace was evident, but goals eluded him.

In Perth he picked up another, his fifth in all competitions so far this term, and perhaps should have had one more. In total last season, he only scored six in the Scottish Premiership.

“He is getting the reward for all that work by scoring consistently,” Rodgers said. “It’s maybe something he could have been better at, but he’s getting into good positions now.”

It’s not just Maeda in a good position. Celtic couldn’t be better placed to take on Dortmund.

All this was achieved on Saturday with Reo Hatate, James Forrest and Idah sitting on the bench for 66 minutes.

Cameron Carter-Vickers was out injured, while Luis Palma was absent from the matchday squad too.

Even without such players, Rodgers saw everything he could have wanted to see. The rest of Scottish football will want to be shutting their eyes.