Despite having won 4-1 in the first leg, the Catalans crashed out of their quarter-final after losing 3-0 in the return fixture in the Italian capital on April 10.
Three days earlier, Barca had named a strong team for the 3-1 win over Leganes at Camp Nou, despite them holding a nine-point lead at the top of the table before the game.
Suarez has admitted he went into the Roma trip feeling fatigued after playing 90 minutes of the Leganes match – something he hopes will not be repeated in 2018-19.
"I really regret the game before against Leganes at home," he told RAC1.
"We had a big advantage [at the top] and in three days we had the [quarter-final] against Roma, but I played the whole game.
"You [go into the game] a little worn down, but you become aware of these things. The coach spots these details and I think it will help manage the squad this year in that sense."
Ernesto Valverde's men kick off this season's Champions League campaign against PSV on September 18.