The 31-year-old former Spain international moved to Elland Road from Dubai-based Al-Nasr last summer on a six-month loan deal.
It is understood that agreement had a clause allowing Leeds to make the deal permanent in January, something that Monk expects to be triggered.
“That is the plan,” said the United head coach when asked if Hernandez will stay at the Championship club beyond the window. “Pablo is committed to us, he is enjoying his time here and he has been a valuable player for us with his experience and quality.
“I don’t envisage a problem with that situation. I know Pablo wants to commit and from my understanding that is the way it will be.”
Hernandez has missed the last three games with a hamstring injury that will also keep him out tomorrow at home to Aston Villa.
Kemar Roofe, outstanding against Liverpool in Tuesday’s League Cup quarter-final defeat, will again deputise in the televised clash with Villa that could see Pontus Jansson return after illness and suspension.
The Swede has returned to training this week and is joined in the squad by Liam Cooper and Eunan O’Kane, who were both substituted at Anfield due to injury.
Having the trio back is a boost for Monk, who insists it is too early to talk about other possible signings when the window opens on January 1.
“We have been quite unfortunate with injuries,” he said.
“The majority have been impact injuries through tackles and things you can’t control.
“We haven’t got the biggest of squads but, in terms of improving it and helping it in January, it is a little bit early to talk about that right now.”
By January, Leeds could have a new investor on board with Andrea Radrizzanin having revealed talks were on going with Massimo Cellino about a deal that would see 50 per cent of the club bought upfront with an option to take full control at the end of this season.
Asked about a potential takeover, Monk insisted his only focus was the football. “We have a lot of games and there’s not a lot of time to think about anything else.”