The Nigeria international is available from La Dea this summer, but at 27 Vieri says there could be a debate about his age.
However, he also told told La Gazzetta dello Sport: "I'd always lean more towards young players, because they always go at full speed. In Miami, I played padel with Nasser Al-Khelaifi, and he told me something that explains a lot: 'Luis Enrique doesn't want players over 28.'
"I agree with Luis Enrique. But if Lookman has the experience, it's a different story: he's someone who makes the difference, he changes matches. Someone like Lookman should always be signed, if possible."
On new Inter coach Cristian Chivu, Vieri added: "Inter wanted a young coach with fresh ideas: Chivu is one, and he has them. But he would need more time than is usually given to Inter, Milan, and Juve in Italy: I hope they give it to him."