Striker Gary Hooper (hamstring), defender Thomas Rogne (calf) and winger James Forrest (groin) missed Saturday's SPL clash at Aberdeen, but look set to fly on Monday to Portugal.
Skipper Scott Brown also looks like winning his fitness battle after an ongoing hip problem, while fellow midfielder Joe Ledley is fighting a knock he picked up in last weekend's draw with St Johnstone.
Concerning the Pittodrie clash at the weekend, Lennon said: "Gary won't make it. We are hoping he will start training on Sunday. Lassad Nouioui is back in the squad. Rogne will hopefully train on Sunday.
"Forrest, at first we thought it was a hamstring strain, but it looks like he has damaged a nerve. We are hoping that will settle down and he can travel with us on Monday.
"Brown and Ledley are doubts for Saturday but they should make Tuesday."