It can't be overstated the esteem in which Pepe is still held by his old colleagues.
Lille CEO Marc Ingla -- the man whose project, along with technical director Luis Campos, has seen the club go from relegation candidates to Champions League participants -- and captain Jose Fonte are glowing in their praise.
What stood out most for Portuguese international Fonte during his one year alongside the Ivorian was not his technical or physical attributes -- though he says they are impressive -- but Pepe's willingness to learn.
"He was a very, very astute guy," Fonte tells CNN Sport. "He was very, very calm. He used to study the game -- every game that he played. One hour after he would be watching the game, what he's done wrong, what he's done right.
"So I appreciate that and I like that he wants to improve, that's something very important."
It was former coach Marcelo Bielsa and Campos who first spotted Pepe as an uncut diamond while he was playing for Angers, though Ingla credits the latter for seeing his true potential.
Campos is widely regarded as one of the smartest and most effective technical directors in football and, though he left a year earlier, was key to building the team that led Monaco to the Ligue 1 title and the Champions League semifinals in 2016/17.
Upon leaving Monaco, Campos insisted his work on the Riviera would not be his final "masterpiece" and his acquisition of Pepe was significant in helping turn Lille's fortunes around.
"It was the merit of Luis to see the values and attributes of Pepe and to project those to become an elite player one day," Ingla tells CNN.
Though Lille is undoubtedly a big club in its own right, it can never compete with the financial strength of European football's superpowers, which means Ingla and Campos have to do things differently, namely buying low and selling high.
The pair could be forgiven for being frustrated with this side of the "football business" -- seeing the best young players the club has nurtured depart year after year -- but Ingla sees Pepe's move as something else.
"It was Pepe's destiny," he says of the 24-year-old's switch to Arsenal. "He was committed to the [Lille] project, even if he had the chance [to leave], he stayed with us for two years."
Ingla says the club received offers from Italy and Spain for Pepe's services after just one season at Lille, which included the opportunity to play Champions League football, but believes it is a measure of the forward's character that he decided to stay.
"He was in a mission here at Lille," says Ingla. "Probably for himself to further develop and confirm himself as he did, but he was also attached to the club, to the group in the dressing room.
"He mentioned as well that he wanted to finish the job, he wanted to to leave the club in a European position with a European standing and he wanted to help the group.
"Also he had close friends here in the group, so he wanted to do this adventure with us and for this we are thankful to him -- but also this shows that sometimes there are stories that are beyond the money or immediate success. So that's why we thank Pepe for this journey."
With the help of an even younger supporting cast of Jonathan Bamba, Boubakary Soumare and Jonathan Ikone -- Pepe's "boys," as Fonte describes the close-knit quartet -- the 24-year-old scored 22 goals in Ligue 1 last season to fire Lille into the Champions League for the first time since 2012.
His former captain is in no doubt that Pepe's attributes mean succeeding at Arsenal is almost a formality.
"We all know that he is a super talent," Fonte says. "He is a super fast player, skillful, he's very good in finishing. I think he has all the talent to be a success in the Premier League.
"I think he already showed signs that he can do well in the Premier League. So I just hope that he can keep developing, keep improving, keep that open mind. Learn with the manager, learn with the older players because if he does that, I think he can be a top player."