Co-owner James Spenceley told the Mercury Welch is “devastated” about any offence caused among Hawks’ African American imports Marvelle Harris or Michael Holyfield or among the fan base.

The photo, posted on Facebook in August 2014, is “about four years old”, before Welch moved to Wollongong from Perth and shows Welch in a Steph Curry Golden State Warriors singlet with his face painted black.

Welch spoke to the players at training on Thursday and offered to have one-on-one discussions with Harris and Holyfield to clear the air over the “blackface” controversy, before the team travelled to Brisbane to play the Bullets on Saturday night.

Welch did not respond to phone and email approaches by the Mercury, but in a statement, NBL general manager Jeremy Loeliger said Welch’s actions went against the NBL’s “core values”. “We are very disappointed and have spoken with Mr Welch at length about our position on such matters,” Loeliger said.

“His actions demonstrate a lack of judgement and perhaps more importantly a lack of awareness of the effect of such behaviour, and why it is inappropriate and inexcusable. “It is completely at odds with the NBL’s core values of an inclusive and equitable sport and workplace.”

Dressing in blackface carries racial implications, particularly in American culture, dating back to 19th century theatre involving non-black actors performing stereotypical African American roles. There have been a number of recent “blackface” controversies in Australia including involving Opals player Alice Kunek, who was criticised by teammate Liz Cambage and also AFL star Nic Naitanui, when a young fan dressed up like him.

“It’s certainly inexcusable, that’s clear,” Spenceley said.

“But you have to look at the intent of it and Kim has certainly not had any intention to offend anyone. 

“It was taken about four years ago, when Kim’s a young guy who has made a mistake. While it’s certainly not something anyone should do, I’ve worked closely with Kim since becoming involved with the club and I can defend his character and how hard he works for the club. He loves basketball and he has gone to a party as Steph Curry without realising the implications of his actions.”