Mahrez blasted an 86th-minute spot-kick over the crossbar at Anfield as City and Liverpool played out a 0-0 draw on Sunday.
Last season, City conceded seven goals in two games against Liverpool at Anfield in the league and Champions League; something had to change and there was a distinct difference to the way his team approached this fixture.
Mahrez had a golden chance to give City their first Premier League victory over Liverpool at Anfield for 15 years when the visitors were awarded a penalty in the 84th minute.
"We know Aguero is the penalty taker, but that is how far the analysis has gone now".
Pep Guardiola refused to criticise Mahrez, who joined City from Leicester in the summer, and praised his "courage" for stepping up, with Sergio Aguero already off the field. "Riyad feels deflated, he feels he has let us down", he said.
And with Liverpool heading into the worldwide break level with City and Chelsea on 20 points, Klopp took a positive stance. Liverpool was never able to build up the sort of momentum it had for spells all three of the games it won against City last season.
India vs Windies, 1st Test, Day 2, Rajkot
Once Shikhar Dhawan was left out of the two-Test series against West Indies , the path was clear for Shaw to make his debut. And Shaw finally departed in the final over before the break when he tamely chipped a return catch to Bishoo.
They now sit level at the top of table, with Chelsea, on 20 points after eight games of the season.
Alexandre Lacazette and substitute Pierre-Emerick Aubameyang both scored twice, with Aaron Ramsey also netting just 39 seconds after coming on as a second-half replacement.
It is perhaps understandable they would struggle to deliver the stellar figures they produced last season and there is still plenty of time for them to punish opponents again, but against City they were nowhere near their best.
"I am really happy with what the boys did today", Klopp said. As it was we didn't score and they could have got a goal so we had to stay switched on.
Their west London neighbors Chelsea have made an altogether more impressive start to the season and remain undefeated with nine wins from 11 competitive games this season.
"Now the players go off and play the Nations League which is the most senseless competition in the world of football", said Klopp, who urged the soccer authorities to look at the issue of players being overused. "I want to keep doing it and keep everyone happy".
"He said "it's too early" to determine the extent of his injury, but that the midfielder had insisted it wasn't a "'big one'".