Barcelona coach Luis Enrique felt his team looked jaded as they claimed a 2-0 win over Valencia in La Liga.
Luis Suarez followed his midweek brace in the 3-1 UEFA Champions League triumph at Paris Saint-Germain with a first-minute opener at the Camp Nou on Saturday.
But the league leaders turned in a laboured first-half display as Valencia captain Dani Parejo had a penalty saved and Andre Gomes hit the post for the visitors.
Lionel Messi sealed the points deep into stoppage time with his 400th Barcelona goal but afterwards Luis Enrique suggested his players were "empty" after their exertions this week.
"It was a great start to the game with that goal in the first minute, but from there we had problems," he told a press conference.
"We committed uncharacteristic errors, we had more problems than usual to approach the opposition goal.
"They had a lot of chances and they deserved better.
"After the break we made some changes and we played the game we wanted to do.
"This is a great result. We must congratulate the players because they are empty."