The 2021 summer transfer market has been largely subdued due to the economic crunch caused by the COVID-19 pandemic. Although Manchester City splurged £100 million on Jack Grealish and Chelsea spent £98 million on Romelu Lukaku, most other clubs have had to do with less extravagant signings.So far, only the Premier League has seen massive expenditure across the division. England's top-flight has spent €1.02 billion on transfers this summer. Alternatively, La Liga has seen the least transfer expenditure, amounting to just €152.3 million.Only Atletico Madrid splashed some cash on Rodrigo de Paul, with Barcelona and Real Madrid largely content with free transfers and getting rid of deadwood. The Bundesliga and Serie A have seen €340.3 million and €446.6 million spent so far, respectively.With no other club apart from City and Chelsea looking set to break their transfer fee records this summer, we take a look at the record signings of 10 of Europe's most popular clubs.#10 Jack Grealish | Manchester CityJack Grealish in action for Manchester City against Norwich CityGiven the sheer volume of money Manchester City have spent in recent years, it is surprising that their record signing only arrived this summer. But Jack Grealish is now a Cityzen and it remains to be seen how he fits into Pep Guardiola's plans.The 25-year-old, signed for £100 million from Aston Villa, has already featured as a left-sided midfielder and left-winger for Manchester City. While he impressed in both positions, it was as a left-winger that Grealish scored his first City goal, netting against Norwich City this weekend.Man City fans have one Jack Grealish verdict after first goal vs Norwich City #MCFChttps://t.co/ArEQKsZySq— Manchester City News (@ManCityMEN) August 21, 2021The Sky Blues have one of the most talented footballers going around at their disposal and Grealish is bound to only improve an already stacked side. City may not have needed him, with a striker still sorely required, but there is little doubt about Grealish's quality regardless of where he is deployed.#9 Romelu Lukaku | ChelseaRomelu Lukaku in action for Belgium during Euro 2020Romelu Lukaku returns to Chelsea as one of the best strikers going around. The Belgian, who signed for £98 million from Inter Milan, helped Inter win the Serie A title last season and broke Juventus's monopoly. Both Timo Werner and Kai Havertz struggled to finish chances last season and with Olivier Giroud departing, Lukaku will shoulder the goalscoring responsibilities.The 28-year-old returns to Stamford Bridge having scored 64 goals in 95 matches for the Nerazzurri. Lukaku also has 64 goals in 98 matches for Belgium and is his nation's leading goalscorer. With proven Premier League experience as well, he could very well prove to be a shrewd signing for Chelsea.#8 Eden Hazard | Real MadridReal Madrid's Eden Hazard has struggled with injuriesEden Hazard has simply struggled since signing for Real Madrid in 2019. Arriving from Chelsea for £89 million, the Belgian has made just a measly 44 appearances for Los Blancos in two years. In those appearances, he has just five goals and nine assists as his dream move seems to have turned into a Spanish nightmare.There are reasons to be positive, however, with Hazard displaying glimpses of brilliance from time to time. Carlo Ancelotti's return to the Bernabeu bench is also expected to bring the best out of the former Chelsea winger. Hazard even registered a delicious assist on Matchday 1 of the 2021-22 La Liga campaign.ICYMI: .@hazardeden10's INCREDIBLE ASSIST vs #Alaves.(Both of our videos got copyrighted, so converted it into a GIF 😉) pic.twitter.com/sJGg39xemg— E. Hazard Tweets (@EHazardTweets) August 15, 2021Perhaps, this could be the season when we see the best of Real Madrid's number 7 after two years ravaged by fitness issues.