Arsenal manager Arsene Wenger has used Ousmane Dembele's lucrative switch from Borussia Dortmund to Barcelona as an example of how the amount of money now being spent on football transfers in an escalating market is "completely disconnected" from reality and the truth.

Dortmund parted with just €15m (£13.7m, $17.8m) to sign Dembele from Rennes in May 2016 and, following one season in which he scored 10 goals and registered 22 assists in 50 appearances across all competitions, last month sold him on to Barcelona in a deal that could eventually be worth nearly €150m.

Such an exorbitant fee saw the teenage French international follow Paris Saint-Germain's Neymar - the player he has been bought to replace - as the second most expensive footballer in history.

Rennes are also believed to have retained a hefty 25% sell-on clause, meaning they set a new club record for the most money ever received for a player without lifting a finger.

"The amount of money is completely disconnected to reality and the truth," Wenger told beIN SPORTS after confirming that Arsenal would likely have to spend between £60m and £70m to replace Alexis Sanchez next summer.

"I give you one example: no matter how well you work as a football coach... Dembele last year was 15. This year, 150. No matter how well you work on a football pitch, you cannot make a player go from 15 to 150. But the calculation between investment and what you can get back is gone. It is just 'can you afford to buy, or not'?"

Dembele was unquestionably the headline capture of an extremely testing summer for Barcelona, who recruited four other new players in Marlon Santos, Gerard Deulofeu, Nelson Semedo and Paulinho but were unable to complete moves for high-profile targets such as Liverpool playmaker Philippe Coutinho, PSG midfielder Marco Verratti and former Real Madrid winger Angel Di Maria.

Arsenal also endured a difficult and underwhelming window that only served to magnify their disappointing start to the 2017-18 season, with powerful defender Sead Kolasinac arriving on a free transfer from Schalke and striker Alexandre Lacazette acquired from Lyon in a club-record £46.5m deal.

Wenger revived his on-again, off-again pursuit of Thomas Lemar late on deadline day, although the versatile midfielder eventually opted to remain at AS Monaco. That decision meant the Gunners, who lost Alex Oxlade-Chamberlain to Liverpool, pulled the plug on the proposed £60m sale of contract rebel Sanchez to Premier League rivals Manchester City.

Speculation regarding the likes of Kylian Mbappe, Riyad Mahrez and Julian Draxler also predictably came to nothing, leaving supporters with a familiar feeling of frustration.

Ousmane Dembele
Ousmane Dembele could make his Barcelona debut against Espanyol on Saturday LLUIS GENE/AFP/Getty Images