Ki, signed by Rafa Benitez last year, last started a Premier League game in August.
And the 30-year-old – who will miss this afternoon’s game against Burnley at Turf Moor – is said to be looking to leave St James’s Park in the New Year.
Bruce, meanwhile, is looking to strengthen his midfield in the transfer window.
Asked if Ki, out of contract next summer, had a future at Newcastle, head coach Bruce said: “I'm never going to rule out anyone.
“(Javier) Manquillo, (Federico) Fernandez, (Ciaran) Clark have all come in, and probably never got much of a look in at the start. I'll never, ever write anybody off.
“The opportunity’s the same for them all, and I think that's important when you're trying to create a spirit. If you do get a chance, take it. Ki’s been unfortunate but with Jonjo (Shelvey), Isaac (Hayden) and the Longstaff (Sean and Matty) brothers, he has got a bit of competition.”
Ki – who hasn’t featured since the 5-0 defeat away to Leicester City in late September – has been unwell.
“He hasn't been very well,” said Bruce, who could recall Sean Longstaff to his midfield against Burnley with Jonjo Shelvey doubtful with a calf problem. “He's been sick, but he's OK now he's got through it, but he hasn't been very well.”