The youngster was close to joining the Blues, but the deal collapsed before Tuesday’s deadline.
"In the end, we didn’t come to an agreement on Jamie because we have different ideas about the player’s current value,” he told the media.
"But the talks were very, very respectful. We have been in very good dialogue with Chelsea for many years.
"And yet we have a different point of view and are happy that Jamie will now be part of our team at the Club World Cup and are delighted that he is staying.
"I’m not responsible for the late offer. But of course I still have to deal with it and that’s what we’ve done.
"Let’s see how things develop in the future."
Chelsea are expected to revisit a move for Gittens when the transfer window reopens, with the player hoping Dortmund will lower their £55 million valuation.