Emegha, the Strasbourg captain, has agreed to join Chelsea in 2026, with the news announced last week. He was then booed on the weekend before victory over Le Havre on the weekend.
Keller told L'Equipe: "When Emmanuel arrived here, he was being pursued by all the big clubs in England and Germany: thanks to BlueCo, he arrived in Strasbourg.
"After an extraordinary second season, we received offers from Italy, England, and Germany. We sat down with the player, his agent, the owners, and me. The priority was to keep him, because he's a striker, a leader, and he carries everyone along with him.
"He wanted to stay; he turned down ten offers this summer. I don't want him to be booed: he doesn't deserve it."
Why Samuels-Smith moved to Swansea
Keller also explained why Ishe Samuels-Smith did not arrive from Chelsea and instead moved to Swansea City.
He said, "Ishe belonged to Chelsea. We were looking for someone to play on the left or as a left centre-back. I didn’t know him at the start, but the sporting director and Liam (Rosenior) did.
“After a few weeks, with the player, the staff, and Chelsea, we felt it would be difficult for him to play right away. Together with the player and his family, we decided that an intermediate step was better.
"The transfer was cancelled, no money moved between Chelsea and Strasbourg. We prioritised the player’s well-being and his playing time.”