The Argentina forward, who has scored 331 goals in his 399 appearances so far, was included in Martino's 18-man squad for the cup clash, but Andres Iniesta misses out as he continues to recover from a knee injury he sustained in the goalless draw at Atletico Madrid on January 11.
Messi himself has only recently returned from a two-month injury lay-off caused by a hamstring problem, but Martino is not concerned he may be demanding too much of the player too soon.
"There is no need to think about Leo as a footballer coming off an injury," the Barca coach told a press conference on Tuesday.
"He has played the last two games, feels fine and will continue playing. When we decide to rest him, then he will rest."
Messi, four-times winner of the Ballon d'Or, has come a long way since making his debut for the Primera Division leaders in 2004 aged 17 years.
The 26-year-old striker, who has never been sent off, posted his best scoring record in the 2011-12 season when he notched 73 goals in 60 games for the Spanish champions.
The Argentina star has scored 14 goals in all competitions so far this season, despite his two-month stint on the sidelines, and he can add to that total at the Ciutat de Valencia on Wednesday.
Alongside the three-time Golden Boot winner, who has won 21 pieces of silverware at the Nou Camp, Dani Alves and Carles Puyol - who both missed the 1-1 league draw against the Valencia-based side on Sunday - have also both been named in the squad.