Speaking exclusively to skysports.com, Longo insisted that if his side cannot come through a tricky test against Sparta Prague and put themselves in the next round, it will not see an exodus.
"I am confident that we can go on in this competition," said Longo.
"But, in any case, we will go on with the current squad until the very end of the season.
"In June a lot of things could change of course, but certainly not in the January transfer window."
Lazio are still battling against financial problems - with a key shareholders meeting expected to increase share capital.
"It is a fundamental step to guarantee the club's participation in Serie A and the Champions League," added Longo.
"Therefore I wish every single share holder to attend the meeting."
