The winger left for England for a fee of €30m.
"We agreed: It had to be a sum that would enable us to tackle a few projects here in the long term. For example, the construction of the new office," Bungert told Kicker, "we want and need to generate a transfer surplus, also in order to deal with infrastructural issues.
"This principle has made us an economically healthy club for decades. But we also used a good portion of the sum to bring in three more reinforcements. "
He also said: "We will not be able to replace Brajan or Sepp (van den Berg), who each moved to or within England for 30 million euros, one-to-one. We are bringing in players with great potential who can develop. Sepp and Brajan were also nowhere near the level they were at when they left us a year ago."