“No man is truly great who is great only in his lifetime. The test of greatness is the page of history” – William Hazlitt. For Pep Guardiola the question is: does he need to overcome a so-far fatal flaw of overthinking selection and win the Champions League for Manchester City in order to be ranked in the all-time managerial pantheon? Or does a CV that already includes two Champions League titles with Barcelona and three Premier League titles and a domestic treble for City make a nonsense of the debate? This is the fascination as his team roll through another Champions League campaign which, if it ends in triumph, will surely finally silence his naysayers. City’s 5-0 obliteration of Sporting on Tuesday was the latest evidence of the ruthless winning machine Guardiola has built. He is assured of a place in the Premier League managers’ hall of fame, but the doubters put an asterisk next to the Barcelona Champions League wins because he was able to select Lionel Messi. The thinking is that if you take away arguably the best footballer of all time then Guardiola is a manager with a self-defeating inability to stop tinkering when it truly counts, a flaw that proved costly in May’s Champions League final defeat by Chelsea. Then, Guardiola’s XI became a collector’s item for not including his first-choice holding midfielder, Rodri, or Fernandinho. The exclusion of João Cancelo, his playmaking full-back, was a puzzle too. Another selection oddity came when he dropped his kingpin creative force Kevin De Bruyne for the Champions League quarter-final first leg at Tottenham in 2019. End result: no away goal – the method by which City were eliminated after a 4-4 aggregate draw. Has he learned from these selection faux pas? That is the question now that Guardiola’s team are a virtual shoo-in for a quarter-final berth after their rampant night in Lisbon. Afterwards at Estádio José Alvalade, Guardiola emphasised, as he likes to, that there can be no guarantees. But his squad are the Champions League favourites for a reason and no opponent will wish to be drawn against them. Just as clear is the bigger-picture stuff he points to when the question of him not having claimed the Champions League with City is put to him: that the fact his side are always “there” as contenders for the big prizes should be the true measure of his achievements for the club and (by inference) of his race as a manager. One way of assessing what Guardiola constructs at City is the length of his tenure. In the summer it will be six years since he replaced Manuel Pellegrini. A half-decade and more at any elite club in today’s boom-and-bust managerial merry-go-round is a relative aeon and casts Guardiola as a throwback to the all-powerful manager who serially accumulates silverware. The last of these was Arsène Wenger, who four years ago ended a 22-year tenure at Arsenal, his exit written up as the final sighting the phenomenon of the manager who sticks around long enough at a club to create his own, gilded era. Another example, of course, was Alex Ferguson, who started at Manchester United in 1986 and exited in 2013 after 13 titles and two Champions League victories. Guardiola insists he will not remain at City as long as Ferguson did across town. He may not need to because he seems intent on piling up trophies at dizzying speed. Whereas Ferguson needed seven years to claim his first league title at United, Guardiola took two. Guardiola, like Ferguson, successfully defended that first crown and his three titles have come in fewer seasons than United’s first under Ferguson. The latter, though, walked into a club in serious disarray and required time to bring it under his control, and he remains the manager par excellence: a one-off genius. Although Guardiola took over a team that had been champions only two years before, his relentless pursuit of excellence is certainly Fergusonian. The kind of performance they put in against Sporting, champions of Portugal, has become par for the course. But the bar set by Guardiola for his side should not be taken for granted. Under him City are occupying rarefied air but the stratosphere is yet to be reached. A team featuring the glittering talents of De Bruyne, Rodri, Cancelo, Phil Foden, Bernardo Silva, Kyle Walker, Rúben Dias and Ederson have to become champions of Europe to seal immortality. Lead them there and Guardiola will join them. Fail and the question may linger about just how great he is.