Furman, 24, earned recognition at the highest level with the country of his birth for the first time this season and is expected to be among the South African squad for the African Nations Cup in January.
But playing at the highest level has come at a price for Furman, who returned from October's internationals to find James Wesolowski and Robbie Simpson in fine form.
A spell on the bench followed and, although the player has now re-established himself in Paul Dickov's engine room, he is realistic about the situation.
"It was obviously a frustrating time for myself," Furman said. "I went away with South Africa and whilst I was away the other lads were playing well.
"The gaffer is very fair and he says if you're playing well you deserve to keep your shirt.
"I was very frustrated but I just got my head down, worked hard and won my place back so, in that respect, it's very satisfying."
He added: "It's all part and parcel of it. There's no international break for League One so I'm going to miss games here and there.
"You've got no right to get straight back in the team, it doesn't matter who you are.
"It's disappointing being out on the bench but if the boys do well when I miss games I've got to work to get back in."