Xavi is urging Ousmane Dembele to "make an effort" after contract negotiations between the Frenchman and Barcelona hit an obstacle.
The 24-year-old has entered the final six months of his contract at the club, meaning he is able to begin talking with other clubs over a free transfer at the end of the season.
Dembele's Barca career has been largely disappointing since joining from Borussia Dortmund for a reported €105million in 2017, with injuries restricting him to just 86 LaLiga appearances from a possible 165.
Yet, ever since Xavi was appointed as Ronald Koeman's replacement in November, the new coach has frequently spoken of his admiration for Dembele, repeatedly backing him to be the best player in the world in his position.
Xavi remains hopeful in light of rumours suggesting Barca and the player's representatives reached something of a stumbling block in talks, though he wants Dembele to play his part as well if he truly wants to stay.
Asked about the apparent "tension" encountered in negotiations, Xavi told reporters: "I am not disappointed. It's a negotiation.
"Agents are difficult. At Barca we have a clear position and it is in progress, it's not over. I'm optimistic and I hope that Ousmane makes an effort. He has a fantastic proposition [but] there is always a tug of war.
"I hope he can stay because he is a player capable of making a difference and could be the best footballer in his position. It's an opportunity for him and he can't miss it.
"I don't think he'd be happier elsewhere than he is here. Barca is the best club in the world, the sporting project is going to be more important than economic [aspect], and I have let him know. That is why I am hopeful.
"I naturally told him that we need him. He is an important player for us. He knows that the project is very interesting for him. The economic issue does not concern me."
One player being linked with joining Barca is Alvaro Morata.
Reports suggest Xavi wants to bring the Atletico Madrid-owned striker back to Spain from Juventus.
While it would seemingly be a complicated deal – and that is before you consider Barca's need to offload players before registering new ones due to their salary limit – it is one that seems to make sense on the face of it.
Though Ferran Torres has arrived from Manchester City, Xavi has appeared unconvinced by his options in the striker role, with Luuk de Jong supposedly set to have his loan from Sevilla terminated, though the coach was reluctant to talk about Morata.
He said: "Let's talk about the players we have. Ferran Torres and [Dani] Alves are going to improve our squad.
"They are very good for our style of play. The rest are theories and that's something that does not concern me."