Merson expressed his thoughts on the deal in his Sky Sports column, stating that he doesn't believe there was a need for another winger after Madueke's arrival.
"I am flabbergasted by Arsenal signing Noni Madueke," Merson wrote. "Chelsea just won't believe that this deal has come to them. They won't believe their luck."
He questioned the logic behind the signing, suggesting that it might be a way to facilitate the sale of another player, such as Bukayo Saka.
"If fit, he plays. So why do you spend £52m on a backup for him?" Merson asked.
