Barely weeks after Gasperini left Atalanta for Roma, Lookman saw a bid from Inter Milan rejected by La Dea. The Nigerian has since made a public transfer request and gone AWOL from Atalanta training.
Gasperini told Sky Italia: "I can only say that I'm sorry, because we run the risk of remembering these players only for the last episode and not for the beautiful moments we shared together.
"I'm sorry for both the boy and the club, I hope it's resolved soon."
Meanwhile, on his youth plans with Roma, Gasperini also said: "When we first spoke with the club, this was precisely the intention. It filled me with enthusiasm, given that I've always done it throughout my career.
"This is something new in Rome; it could be something different. It inspired me to think: 'I've done it well in many places, it would be extraordinary if I could do it in Rome too'."