Arsenal are willing to sell the 26-year-old but are determined to do so on their own terms rather than accept a cut-price deal.
That is bad news for Hamburg SV, who had Vieira on loan last season and hope to sign him permanently for a fraction of Nottingham Forest's proposed fee.
According to Hamburger Abendblatt, Hamburg's pain threshold sits at just under €10million, far short of what Arsenal are demanding.
Hamburg had been banking on no serious rivals emerging for the Portuguese, but Forest's offer appears to have ended that hope.
Vieira impressed on loan at Hamburg last season, contributing seven goals and six assists in 31 appearances as the newly promoted side secured Bundesliga survival.
That form stood in stark contrast to his time at Arsenal, where he managed just three goals in 49 appearances, a disparity that has strengthened the Gunners' resolve to hold out for a higher fee.
Despite repeatedly stating that he could imagine staying in north London, the clear direction of travel now points towards a departure this summer.
Vieira had hoped for quick clarity on his future, according to reports in Germany, but will likely have to wait a little longer before his next destination is confirmed.
Hamburg sporting director Kathleen Kruger admitted that hopes of keeping Vieira are fading given the figures being discussed elsewhere in the market.
"I would love for him to wear the HSV shirt next season. But players of this quality are priced on a shelf that isn't ours," Kruger said.
With Forest now firmly in the mix and prepared to match Arsenal's valuation, Hamburg face a real battle to retain a player who proved instrumental in keeping them in the Bundesliga last season.
Vieira originally joined Arsenal from Porto in 2022 and has since had two separate loan spells without nailing down a regular role at the Emirates Stadium.
With only a year left on his contract, this summer is one of Arsenal's last chances to recoup a fee for a player no longer part of their long-term plans, and Forest's interest only adds to the pressure on Hamburg to act.