Valdes announced last season he was quitting because the pressure of being Barca’s first choice for a decade had taken its toll and he wanted to experience different cultures and different languages.
Speculation has mounted in recent weeks Valdes could accept a lucrative offer from Ligue 1 side Monaco or English Premier League club Manchester City.
“Marc has informed us that he won’t accept our offer and therefore will not extend his contract with us,” Eberl said on Gladbach’s website (www.borussia.de) on Monday.
“It’s a great shame from our point of view but we must accept it,” he added.
“We suspect that he will join the club (Barca) about which there has been a lot of speculation.
“I fully expect that we will have to find a new keeper for next season.”
Valdes, who returned from injury in Sunday’s 4-0 La Liga win against Elche, has made a host of vital interventions this season that helped avert an early setback to the Spanish champions’ bid for a fifth La Liga title in six years.
He has been praised by coach Gerardo Martino and team mates for his professionalism and his form has prompted calls for Spain coach Vicente del Bosque to give him the keepers’ spot ahead of captain Iker Casillas.
His decision to leave Barca, where he has spent his entire professional career, means they will need a replacement with similar ball playing skills who can fit in with the club’s style of playing the ball out from the back.
Eberl said Gladbach had given Ter Stegen, who has a market value of 11 million euros ($15 million) on website Transfermark上海按摩,m, assurances when he extended his contract two years ago that he could leave if a “top club” came calling.
“This situation now seems to have arrived,” Eberl added.
“I expect we will come to an agreement with this club on a transfer.
“Borussia is not in a position to ignore exorbitant fees. We must see it as an opportunity and bring in new players with the proceeds.”
Ter Stegen made his debut for Germany in a 5-3 defeat against Switzerland in May 2012, the first of three appearances including a 4-3 loss against United States last June when he scored a bizarre own goal.
He suggested he would remain with Gladbach until the end of the season.
“It was not an easy decision,” he told the club’s website.
“I have an unbelievable amount to thank the club for and I still want to put in more effort for them. We want to perform well as a team in the second half of the season.”
($1 = 0.7330 euros)
(Writing by Iain Rogers in Madrid, editing by Pritha Sarkar)