The Argentina captain, who scored four goals and set up four in Barca's five opening La Liga matches, was replaced during Wednesday's game against Atletico with a groin injury that will sideline him for three weeks.
"Not to have Messi is always difficult but we have proved that we have enough resources to not depend on him," Luis Enrique told a news conference on Friday.
"To have a player injured is bad news, even worse when it's the best player in the world.
"In order to win titles, we have to overcome situations like this one, having to do without important players.
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"The team did fantastically well last season without him."
A knee injury kept Messi out for two months last season but Luis Suarez and Neymar picked up the slack for the Catalan giants, scoring 20 of Barca's 23 goals.
Barca signed Paco Alcacer as their fourth-choice striker from Valencia last month and the Spain international could have a more prominent role, starting with the trip to Sporting Gijon on Saturday.
"We have options to replace Messi and we have to evaluate them," Luis Enrique said.
Alcacer did not impress on his debut this month, a 2-1 home loss to Deportivo Alaves, making only eight passes in 66 minutes before being replaced by Suarez.
"Alcacer has nothing to prove," the coach said. "He has already showcased his talent.
"He is a Spain international and a well-known striker."
Asked if he expected Neymar and Suarez to step up with Messi out, Luis Enrique said: "I expect the best version of all of my players, the same as when we have Leo. I'm not going to ask them for anything extra because they already give that in every game. It's obvious that we are going to experience different situations without Messi but we must adapt."
Barca are third in the standings, three points adrift of league leaders Real Madrid, who visit Las Palmas on Saturday.
Sporting, Luis Enrique's home club, followed a 5-0 loss at Atletico Madrid with a 2-1 defeat at Celta Vigo on Wednesday.
"It's going to be a tough game and we will need a good performance," Luis Enrique said.
(Reporting by Adriana Garcia, editing by Ed Osmond)
