The midfielder came on in the 88th minute for Andres Iniesta, wearing the No 15 shirt.
"I should keep working and get to know my team-mates to enter into the team bit by bit."
On the game he added: "Alaves played on the counter, tight at the back, looking to come out with speed after a lost ball or when they won it back."
On Barcelona: "I think the team's doing well, calmly, securely, playing with patience, without haste. The truth is we got a result we deserved."