The Chilean was dubbed online as Manuel Pelligrini in a feature on his backroom staff, and Twitter was immediately lit up with people sharing and spreading the mistake.
"Funny to see Manchester City spell Pellegrini's name wrong on their website," observed Irish football journalist Kevin Palmer, "As if they haven't known he was coming for the last six weeks!"
City swiftly corrected the mistake, but some wondered whether Pep Guardiola would have got the same treatment had he been appointed as manager.
Pellegrini can certainly expect stiffer challenges ahead than the club simply spelling his name correctly.
The manager was bullish in his first interview as boss, telling City TV: "Everyone knows if you arrive at a club like Manchester City you need to win titles.
"I think Manchester City have invested a lot of money to improve the squad every year and try, every year, to win titles. They were not successful in winning some titles but I am sure we are going to win - maybe the Premier League, the Champions League. We will try to win a lot.
"My first message is to tell all the supporters they will enjoy the season. I am sure they will enjoy the way our team will play. We will play an attractive, offensive play."
Having seen his predecessor Roberto Mancini sacked after just one trophyless season, he will know that time is not necessarily on his side.