Manchester City have enjoyed a golden era since Pep Guardiola was appointed the team's head coach back in 2016. The Spaniard is in his sixth season at the Etihad and has cemented the Sky Blues' place at the pinnacle of English football.Guardiola's record at Manchester City is astounding, with 251 wins from 337 games so far and just 50 losses. The club has won ten trophies during that period, including three Premier League titles and four consecutive EFL Carabao Cup triumphs (2018-21).The UEFA Champions League, though, has remained out of grasp, with the Sky Blues falling agonizingly short at the final hurdle in 2021, losing 1-0 to Chelsea.The Pep@GuardiolaTweetsWhen Guardiola is your coach:Man City 700 goals under Pep #Pep #ReInventingTheGame8:41 AM · May 1, 20211851264When Guardiola is your coach:Man City 700 goals under Pep #Pep #ReInventingTheGame https://t.co/wGmliYutT5Several talented players have flourished under Pep Guardiola at Manchester CityPep Guardiola's famous possession-based system not only obtains the desired results but also helps players develop quickly. Midfielders, in particular, have blossomed under the Spanish manager. His emphasis on passing and composure on the ball eventually leads to improved technique and awareness.City Xtra@City_XtraPep Guardiola on #ManCity breaking records: "It means the consistency we have as a team. Not winning a title or final, just winning and winning. One day, they will be broken. All records exist for that, but we're happy." [via @BBCMOTD]9:56 AM · Dec 19, 202169930Pep Guardiola on #ManCity breaking records: "It means the consistency we have as a team. Not winning a title or final, just winning and winning. One day, they will be broken. All records exist for that, but we're happy." [via @BBCMOTD]While the likes of Phil Foden, Riyad Mahrez, Rodri and Kevin De Bruyne have flourished under Guardiola, a few players have failed to adapt to the demanding system. On that note, we look at five Manchester City players who struggled under the Spanish manager:#5 Jack GrealishJack Grealish has not hit the ground running at Manchester City.Perhaps it's a bit too early to label 26-year-old English superstar Jack Grealish a flop. After all, Pep Guardiola's system isn't the easiest to adapt to, especially for a player like Grealish, who was the undisputed main man at Aston Villa.The midfielder was afforded enormous freedom and time on the ball at the Birmingham-based club. He has not settled into his new team, which doesn't revolve around him.Nonetheless, four goals and three assists in 29 games is underwhelming by any standard, but all the more so for the most expensive player in Premier League history.Statman Dave@StatmanDaveJack Grealish in the Premier League this season: 19 appearances 2 assists 2 goals Jadon Sancho in the Premier League since the start of February 2022: 7 appearances 3 assists 2 goals Guess who makes the England squad… 🏴󠁧󠁢󠁥󠁮󠁧󠁿8:20 AM · Mar 17, 2022136231548Jack Grealish in the Premier League this season: 👕 19 appearances🅰️ 2 assists ⚽️ 2 goals Jadon Sancho in the Premier League since the start of February 2022: 👕 7 appearances 🅰️ 3 assists ⚽️ 2 goals Guess who makes the England squad… 🏴󠁧󠁢󠁥󠁮󠁧󠁿 https://t.co/cgtayNbCGvManchester City shelled out an English record fee of £105.5 million to bring Grealish to the Eithad. In hindsight, perhaps, Manchester City would have been better off targeting Lionel Messi and Harry Kane instead.#4 NolitoNolito in action in a Champions League game against Barcelona.One of Pep Guardiola's first signings at Manchester City was that of Spanish forward Nolito from Celta Vigo for just over £16 million. As a youngster, the wideman had trained under Guardiola during their time together at Barcelona.Manchester City@ManCityNolito has joined @SevillaFC...Good luck Nolito from everyone at #mcfcbit.ly/2uxCfag9:49 AM · Jul 16, 201738601033Nolito has joined @SevillaFC...Good luck Nolito from everyone at #mcfcbit.ly/2uxCfag https://t.co/weNuHxeQ5dNolito never settled into life at the Etihad and lasted just one season at Manchester City. The Spaniard scored six goals and provided five assists in 30 appearances before being sold to Sevilla for a £10 million loss.