BERLIN -- While Erling Haaland is enjoying the sun in southern Spain to cure his injury, the battle about his future continues.

Rumors might speak of a likely transfer to Real or a solvent Premier League side such as City next summer, but the Norwegian's current club Borussia Dortmund is playing out all cards to keep the striker.

The Black and Yellow rely on a joint venture with the club's supplier Puma. While the club is said to increase the attacker's salary to 15 million euros per season, the supplier is providing a personal contract worth five million per season over five years.

The new deal would secure Haaland's stay until 2023.

Due to his valid contract, the Norwegian goal-machine can use an exit clause worth assumedly 80 million euros in 2022. His market value has grown up to 130 million.

Despite his agent Mino Raiola announcing, his client is prepared to join a leading side at an age of 22, Dortmund is placing all its hopes on a comprehensive package.

Aside from the salary update, Haaland's status as a fan hero might be a significant part.

The spearhead often talked about the "incredible feeling" celebrating his goals in front of the so-called yellow wall in the 2012 German Champions arena.

Up to 25 000 fans turn the stadium south stand into the biggest standing stand in Europe.

Next to Dortmund's efforts, league director, Christian Seifert encouraged the German national league to invest all to keep Haaland as the advanced Youngster is one of the rare attractions next to Bayern striker Robert Lewandowski.

Seifert's suggestion to start league crowdfunding to please the player might have not been meant very seriously. But all actions prove how important the forward is for the league's marketing efforts on the international stage.

As apparent is Dortmund's dependency on his strikers' contributions. This season Dortmund scored 2.875 goals on an average per game with Haaland, but only 1.0 when he was side-lined.

"We lack impact without him," Dortmund coach Marco Rose said.

The decision about the striker's future hasn't yet been made says Norwegian football icon Jan-Aage Fjortoft.

"As always when top-class players have to make such a decision, they investigate the entire package. Then it's about their salary, the sportive possibilities, and their well-being around the club," the 54-year-old said.

Dortmund supporters hope the Haaland fraction might take a close look at the situation of Jadon Sancho. The Three-Lions-striker left for United this summer but couldn't achieve his breakthrough in a well-equipped squad.

The right timing seems essential for a transfer to proceed on the way to world-class. "Of course, the chance to win titles is important, but players need to be secure they can enjoy the new club's trust and play regularly," Fjortoft added.

Dortmund seems aware it has to keep title ambitions alive to address the spearhead demands, and its chances in the ongoing battle might be minor. But at present, it seems more than a bold dream to discover the race isn't yet lost.