We may talk about their winning back to back titles, and we may talk about their run to the champions league final. But when we stack them up against the real heavyweights like Barcelona, Real Madrid, Manchester United, Bayern and Chelsea, Dortmund for all intents and purposes are a small club. And when players achieve a level of success at small clubs (unless they are Steven Gerrard or Alan Shearer) they tend to move on. This is the situation with Reus and Hummels, both players have become key players and the top players in Jurgen Klopp’s side but Dortmund cannot offer them the kind of salaries the big teams will be willing to offer, the world wide exposure those teams will be willing tomoffer or the success those teams will be willing to offer.
People will talk about Kagawa as a Manchester United flop forgetting that Manchester United have delivered a league title to Kagawa, doubled his salary and had enough brand equity to take him on a tour of Asia making him a bigger sensation than he already was there. These big clubs and their brands have commercial viability something Dortmund are a few years away from. In those few years, Hummels and Reus would be past their peak and will not really reap the financial fruits their talents could have brought them so they will be looking to move. Clubs like Manchester united, Monaco and Manchester City can guarantee Money while Real Madrid, Barcelona and Bayern Munich would give money and trophies and Klopp must know this. Because Dortmund as a brand isn’t big, they don’t have the exposure to rake in as much commercial dividends from the players as a club like Manchester United or Barcelona so their only benefits from keeping the players would be on the pitch and they would eventually lose those talents for free much like they lost Lewandowski and his stay was futile because he didn’t fire them to a league, cup or champions league trophy and Dortmund still ended up paying for Immobile when they didn’t benefit from Lewandowski.
Klopp knows how to Identify top players on the budget so he had better let Reus and Hummels go, use the money to build a team that can succeed and when Dortmund is big enough, he can hold on to his big names but not quite yet.