Messi - who missed both friendlies for Argentina during the international break - was a doubt with a hamstring injury.
Coach Ernesto Valverde told reporters the club would wait before making a decision over whether the 30-year-old would take part in their La Liga clash.
But the forward has proven his fitness enough to take his place in an 18-man group named by Valverde.
Luis Suarez returns from suspension after missing Barca's last game, a 2-0 home win against Athletic Bilbao, with Nelson Semedo and Denis Suarez also included after recovering from injury.
But there is no place for defensive midfielder Sergio Busquets, who is battling to recover from a toe injury in time for the Champions League quarter-finals.
Barca, who have an 11-point lead at the top of the table, host Roma in the first leg of the tie on Tuesday.
Aleix Vidal and Yerry Mina sit out, while left-back Lucas Digne is absent due to a thigh injury sustained on international duty with France.