Alcantara netted a hat-trick in Spain's 4-2 win over Italy in the under-21 European Championship final and has captained the side throughout the tournament in Israel, helping the team achieve a perfect record of five wins out of five. The midfielder was also a key member of the side that won the tournament in 2011.
However, his future at the Camp Nou has been cast into doubt.
Alcantara made just 15 starts in La Liga last season, struggling to hold down a place in the first team, where he faces stiff competition from the likes of Andres Iniesta and Xavi Hernandez.
According to reports in Spain, he has already decided to leave Barcelona, with Manchester United and Bayern Munich reportedly the two clubs that have shown the most interest in him.
Either club could seal his signature shortly by paying his 18million-euro buy-out clause before 31 July, after which his transfer fee will rise. Speaking to radio program Al Primer Toque on Onda Cero, Barca center-back Pique urged his club to hold on to the 22-year-old, who he believes could become as important to the team in the future as Xavi and Iniesta.
"There is a possibility that he could leave but we have to convince him that the best place for him is Barcelona," said Pique. Players in his position like Xavi were patient and they ended up defining an era."
For Pique, the exploits of Alcantara and the under-21s shows that the future of Spanish football is in safe hands.
"When you watch them and see how superior they have been in this tournament you realize that the future is very positive," he said.
The defender also admitted it was likely that the club would sign at least one defender over the summer, but reaffirmed his faith in his team-mate and usual center-back partner Carles Puyol, who is about to undergo a third operation on his right knee in the last 13 months.
Strengthening in defense has become a priority for Barcelona ever since they were knocked out of Bayern Munich 7-0 on aggregate in the semi-finals of last season's Champions League, with Pique having to play alongside the inexperienced Marc Bartra due to the absence of Puyol and Javier Mascherano.
"I understand why Barcelona want to strengthen in the center-back position because last season we suffered a lot from injuries," said Pique. "All the names that have been linked with the club are very good players and we will welcome any new arrival. But I think we should remember we still have Puyol and if he starts to get fit again he will still be among the top five center-backs in the world."