Barcelona manager Luis Enrique are fit to play against Alaves on Saturday (10 September) but failed to confirm whether the duo will make his starting line-up along Luis Suarez. Meanwhile, the boss claimed that Andres Iniesta and Jeremy Mathieu are progressing well, but suggested that the encounter with the Basque side may still come too early for the two long-term absentees to start.
Messi suffered an injury in his groin during the Barcelona's victory over Athletic before the international break but still decided to join the national team for the World Cup qualifiers against Uruguay and Venezuela. However, after playing the first of those games, the Ballon D'or winner was withdrawn after his problems were aggravated.
But the Argentinian has been doing light training with the rest of his teammates this week, and the Barcelona boss said that he is fit to face Alaves, although suggesting he may be rested anyway ahead of Tuesday's Champions League opener against Celtic.
"We had to assess the situation. He trained one part with the team and another alone. He is in a condition to play tomorrow," Luis Enrique said in the press conference ahead of the game. "He is in condition to play. I've spoke with him like I speak with all my players and we know how he is.
"We have to analyse the situation and keep in mind what's best for the player and make sure he's in the best condition possible. There was a report which said what the player has and we have had to evaluate things from there. We have a lot of commitments throughout the season and we always focus on [the best] for the player."
Neymar, meanwhile, only returned to Barcelona from international duty on Thursday after more than three months out, firstly because of his holidays and then due to his participation in the Rio Olympics. Yet, Luis Enrique said that the Brazilian is "in great shape" and ready to play his first game of the campaign for Barcelona.
"Neymar is in great shape, happy for winning Olympic gold with his country, and is motivated to participate," the boss added.
The boss, however, was less optimistic about starting Iniesta and Mathieu as the duo are yet to play since the Spanish Super Cup.
"Iniesta and Mathieu have improved their physical condition but will need minutes to fully recover," the Barcelona boss said, while failing to address the situation of Andre Gomes, after the Portuguese international also suffered a knee injury on international duty.
One way or another Luis Enrique may do some rotations in his line-up ahead of busy week with a Champions League encounter, with Celtic coming only three days after the Alaves game.
"We go into the game on the back of the international break. Depending on the opponent and the situation, I will try to choose the best way of using the players," he said. "In 23 days we have seven matches. We must play a game of Tetris, assess the workload, see what each game requires, which type of players we need for each game. All players will be required, but they know they cannot play all the time, in each game there will be top players on the bench or in the stands. But we all have the common goal of winning titles, and therefore we must be a team, thinking of the overall benefit."
Summer signing Paco Alcacer may be handed his debut following his arrival from Valencia later in the transfer window.
"He (Alcacer) is doing well, very happy," the Barcelona boss said. "He is adapting well as he knows many of the players from the national team and from the rest of the league. He is practically already integrated, with the motivation to help us."