But while Pompey fans poked fun at Steffen while his young Etihad Stadium team-mate racks up the plaudits during an impressive season-long loan spell at Fratton Park, Cityzens fans on social media weren’t seeing the funny side of their No2’s display at Wembley.
Indeed, they were demanding the return of Bazunu following two costly errors by the American in their 3-2 defeat to the Reds.
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But the decision soon backfired, with the Sky Blues keeper badly at fault for the Reds’ second goal.
As he took his time with a back pass, Sadio Mane rushed in to close him down, blocked his attempted clearance and bundled the ball over the line.
Steffen was then criticised for allowing Mane to score with a volley that beat him at his near post – handing Jurgen Klopp’s side a 3-0 lead at half-time.
City made a fight of it in the second half as they scored two unanswered goals to set up a nervy end to the game.
Steffen did well to deny Firmino in the dying seconds – but by that stage, Cityzens supporters on Twitter had already made their minds up.
They wanted Bazunu back at the Ethihad to replace the American.
@BarefootKdb wrote:Just bin Steffen and play Bazunu from next season onwards imo.
@_Yorm commented:Get Gavin Bazunu and James Trafford back in the team and loan Steffen out this summer.
@noisy_requiem posted: Why do we have one of the top rated gk talents in the world on our books in Gavin Bazunu and yet we play this yank.
@Excelsiormcfc said:Bazunu should be our number 2. Ireland no.1, Young and he'll have time to learn under Ederson.
@BackPostHeader remarked: Gavin Bazunu surely the City number 2 next season after this performance from Steffen.
Meanwhile, @hylo64 wrote: Zack Stefan is not even close to being as good a Gavin Bazunu let alone Ederson, before @DhxuvMCFC joined in by saying: Call Bazunu back RIGHT NOW!!
Republic of Ireland fans added to the debate, with @carabini_10 commenting: In fairness, Gavin Bazunu wouldn't have done that, while @TacheyDelBosque posted: Bazunu is so much better than Steffen but glad he's out on loan getting proper game time rather than getting the odd cup game for City.
Yet not letting the moment pass, Pompey supporters also weighed in as they took delight in pointing out how good 20-year-old Bazunu has been for them this season.
The Eire international has played 42 times for Danny Cowley’s side this season, keeping 17 cleans sheets.
That has seen him linked with a move to Premier League clubs and European sides as others look to make the most of his impressive performances between the sticks.
Pompey supporter @jackgareth98 wrote: Zack Steffen is a Poundland Gavin Bazunu.
@brendonvbone said: I could see Bazunu getting the number 2 at Citeh next season. Steffan calamitous again.
Meanwhile, @RoryPeter joked: This Steffen deserves another chance at City next year. He’s miles better than Bazunu. Think Bazunu should stay at Pompey next year.