GOAL - Chris Burton
Speculation continues to rage around the six-time Ballon d'Or winner as his lucrative contract in Catalunya runs down towards free agency.
Fresh terms have been mooted, along with moves to the likes of Manchester City or Paris Saint-Germain, and no formal decision will be made on his next move until the summer.
While Messi is keeping everyone guessing on his plans, Zubizarreta believes a decision has been made, with the former Baca goalkeeper telling Catalunya Radio: "Messi has earned the right to think and to decide.
"The president [Joan Laporta] has already said that he would do everything possible for him to stay.
"From there on, if he decides to stay, then wonderful. If not, then we will have to keep playing.
"And if he does decide to leave - even though I know some people will propose that his shirt number is retired - someone will have to play with the number 10 in the Barça youth team. Life goes on.”
Zubizarreta, who spent four-and-a-half years back at Barca as director of football between July 2010 and January 2015, added on Messi: "In the process of us making our decisions, the things that happen to you have an influence.
"These are the factors that accumulate, but I think that Messi has, more or less, made up his mind.
"The cup final is one of those factors that help to confirm your decision. But I don't think it will be decisive. He is a veteran and we have all had days when we think about giving up football.
"Messi is a footballer in the traditional sense of the word, he is not a marketing product. He's old enough to know that sometimes you win and sometimes you lose, the thing is that he feels good at Barca."
Barca are currently readying themselves for a Copa del Rey final showdown with Athletic Club, with that contest set to take place on Saturday.
Ronald Koeman's men also remain in contention for La Liga title glory, but a Clasico defeat to arch-rivals Real Madrid last time out has left them two points off the pace in third.
Tangible success could go a long way towards convincing Messi to stay put, with the Blaugrana also in the process of identifying summer transfer markets as speculation builds regarding interest in the likes of Erling Haaland, Georginio Wijnaldum and Sergio Aguero.