In total, 71 people were killed when a chartered plane carrying players and staff from the Brazilian football team for their Copa Sudamericana final first-leg match against Atletico Nacional crashed en route to Medellin, Colombia.
Lucas, who knew some of those who died, captained Liverpool to a 2-0 EFL Cup quarter-final win over Leeds United at Anfield on Tuesday and conceded it was hard for him to focus on the task at hand.
"It was a terrible accident. I have a few people that I played with [on the flight], some young players," Lucas told Sky Sports, having led his team in a minute's silence before the match.
"It was very hard for me to play tonight because I know a lot of people there.
"We just hope that the families have the support that they need and the victims rest in peace."
On Tuesday, Colombian officials revised the death toll down from 75 after learning four people did not board the flight.
Six people, including Chapecoense players Alan Ruschel, Jackson Follmann and Helio Hermito Zampier Neto were named as survivors from a tragedy that drew words of sympathy from across the football world.
"It is an enormous tragedy," said Barcelona head coach Luis Enrique.
"I think it is mandatory to carry out a deep investigation to confirm every security measure was in place.
"Obviously, we are not talking of a situation which affects only sport, but families and many different persons. We have to lament it deeply and sending out all our condolences."
Luis Enrique's Real Madrid counterpart Zinedine Zidane said: "I would like to send my support and the support of my club to all the family and friends of the people that died in this accident in Colombia.
"And also, of course, to the club Chapecoense and all of their supporters. We are very sorry for what happened."
In Chapeco, fans gathered at the team's Arena Conda and took to the streets in large number to pay tribute to their fallen heroes. The Brazilian Football Confederation (CBF) has declared seven days of mourning, with all games this week cancelled.