The 27-year-old, who has a record of 7-3-1, was due to fight Sid Razak on September 23. The contest represented his second fight since taking a five-year break from the ring.
Wale is now recovering in hospital.
The Barnsley-born fighter, brother of former Prizefighter semi-finalist Josh Wale, 23, is expected to make a full recovery as South Yorkshire police try to piece together the events at around 3.45 pm two days ago.
Brother Josh, who himself is due to fight on September 3, posted a message on Facebook yesterday morning informing people of the incident and has since updated it as Gwyn recovers in intensive care.
“Hi, just to let everybody know, my brother Gwyn is in intensive care after being stabbed in the heart,” wrote Wale.
“He is a fighter, though. Thanks for all your calls and text. I will pass them on to Gwyn. Thanks, Josh.”
Yesterday afternoon Wale wrote, “Gwyn has woken up and is making good progress.
“They are doing a great job on the intensive care ward. Thank you to everybody for your kind support.”
A Police spokesperson said, “Police were called to an incident at Becknoll Road, Brampton, Rotherham, at about 3.45 pm on ThursdayAugust 2525.
“A 27-year-old man has been taken to hospital with non-life-threatening stab wounds and is currently in a stable condition. A 44-year-old man has been arrested in connection to this incident.”
Anyone who witnessed this incident or has information about what happened is asked to contact South Yorkshire Police. Call 0114 220 2020 and quote incident 680.