Barcelona coach Xavi confirmed goalkeeper Marc-Andre ter Stegen will miss the Spanish champions' La Liga clash with Rayo Vallecano on Saturday due to back pain.
"Tomorrow Marc can't make it and we have full confidence in Inaki Pena, who is 100 percent ready," Xavi told a news conference Friday.
Pena, 24, is a product of the club's youth academy and has played for the Barcelona first team five times.
Barcelona have been beaten in their last two visits to face Rayo at Vallecas and trail surprise La Liga leaders Girona by four points.
Frenkie de Jong is available after injury but Barca will also be without tireless midfielder Gavi for the rest of the season after he suffered a cruciate ligament injury while playing for Spain last week.
In Spanish media some have looked to blame national team coach Luis de la Fuente but Xavi said the injury was not his fault.
"I have no problem with De la Fuente, it's a problem with the calendar and too many games," explained Xavi.
"With the age (Gavi) is, he's played a lot of games and the calendar is full of matches, and that's the reason for the injury, along with bad luck."
He continued: "He's an irreplacable player for the passion, desire and courage that he puts out there."
Xavi has suggested changes to football's calendar in the past to stop players leaving for international duty throughout the season, and brought it up again.
"A small solution is to play eight or nine months with the club and then have a period for European qualifiers and the Euros," he said.
"It's not easy that each month there's so much travel -- nine months with the club and two with the national team."
rbs/jc