Sa has been the standout number one for the past three years, making a total of 118 appearances in all competitions.
However, for the last two weeks, Wolves have been attempting to sign a new stopper, their initial preference being Arsenal's Aaron Ramsdale.
Having failed to get a deal over the line for the England international, who subsequently signed for Southampton, Wolves opted for Crystal Palace's Sam Johnstone.
As expected, the new arrival was selected between the sticks for Saturday's Premier League fixture at Nottingham Forest, the visitors earning a respectable 1-1 draw.
What did O'Neil have to say on Sa, Johnstone?
After the game against their Midlands rivals, O'Neil was naturally quizzed on the situation with the possibility remaining that Sa could move to the Saudi Pro League or, theoretically, sign for a Portuguese club.
Instead, O'Neil has indicated that the 31-year-old had not necessarily dropped out of his plans, hinting that Sa was only out of his squad at the City Ground for personal reasons.
Speaking to the club's official website, O'Neil said: "There's no situation really. It's an unsettling week, there's a lot going on, Jose had a bit going on, I obviously had a big decision to make around goalkeeping, and we decided it was Sam today.
"But Jose will be back training with a group once he returns from Portugal and the idea is that him and Sam will fight it out.
"I felt that Sam should have the shirt today, but it doesn't mean it's always going to be that way. Jose is a fantastic goalkeeper.
"He's done an awful lot while I've been here, before I was here, so Jose will react in the right way, and he'll know he needs to come back after the Portugal trip and fight for his place like everyone else does in the in the squad."
A closed decision?
With O'Neil and sporting director Matt Hobbs each indicating that Sa will stay put, only a sizeable bid for his signature will change matters.
As a result of his reputation being enhanced since his arrival from Olympiacos and with three years left on his contract, Wolves would want in excess of £10m.
That is the fee that they shelled out for Johnstone, who has played far less football than the Portugal international over the past two seasons.