The long-serving midfielder was not part of the Reds' bloated squad for Friday's pre-season friendly meeting with Wigan Athletic, a few hours after reports emerged suggesting that a £5m deal had been agreed with Serie A side Lazio.
Lucas was asked to fill in a variety of positions last season, making 19 starts in all, but Klopp claims that he is in the dark over the Brazilian's future plans and may omit him from the travelling party that heads to the Far East for the next leg of the club's pre-season preparations.
"I am not 100% sure, but I think for Lucas, [who's had an] outstanding, fantastic time at Liverpool, we should talk about facts and not rumours. Maybe something, maybe not," he told reporters.
"We can only involve 25 players, so if we take three goalkeepers we can only take 22 [outfield players]. Tonight we will make the decision. Maybe the squad will need to be different.
Lucas, who has made 346 appearances for Liverpool during his decade-long stint at Anfield, is due to see his contract expire in 12 months' time.