Defender Winston Reid has signed a new long-term contract with West Ham which commits him until the summer of 2021.
Blackburn have signed defender Doneil Henry on a month's loan from West Ham.
Reus has reportedly been on the radar of Manchester United for some time but speculation over a move to Old Trafford had cooled after he stated last month that he was expecting to stay with Dortmund for next season.
However, Spanish newspaper reports on Monday suggested that Barcelona and Reus have already agreed a deal on personal terms to take the midfielder to the Nou Camp.
Dortmund have moved quickly to dispel the latest rumours, though, with sporting director Michael Zorc adamant that the 25-year-old will not be going anywhere.
"I can definitely rule out a transfer this summer," Zorc said, quoted by Bild.
Reus has a contract with Dortmund until 2017 but reportedly has a release clause of €35million which can be triggered from the summer of 2015.
The Germany international has been ruled out of the upcoming World Cup in Brazil after suffering an ankle injury against Armenia on Friday.