Wissa, 29, was signed from Brentford on deadline day last summer for £55 million — a scrambled acquisition made in the final 30 seconds of the window after Newcastle had failed to secure their primary striker targets following Alexander Isak's record £130 million departure to Liverpool.
He joined alongside Nick Woltemade in an attempt to fill the gap Isak left, and neither has come close to doing so.
The deal was further complicated by a knee injury Wissa suffered in pre-season training just days after signing, which ruled him out for the first four months of the campaign. He scored 19 Premier League goals for Brentford last season but has managed just one for Newcastle this term, and has not started in any of his last 16 appearances.
The Athletic reported on Monday that Newcastle United will actively attempt to sell Wissa this summer before his value falls further.
The club are expected to receive offers in the region of £15-20 million — significantly below the £55 million paid — and must also hand 25 per cent of any sale back to Brentford as part of a sell-on clause agreed when he left Craven Cottage.
Wissa is understood to want to stay at St James' Park but the club are expected to override that preference if an acceptable bid arrives. Newcastle plan to pursue a more established centre-forward this summer to replace both Wissa and Woltemade.