The 23-year-old was taken off at half time in Celtic's 2-1 Scottish Premiership win away at St Johnstone on Saturday, with Postecoglou stating after the game that the attacker was replaced due to fatigue.
"There was a bit of fatigue there, and we were never going to give him too many minutes," the Australian boss told Sky Sports News.
"Again, he has been carrying a heavy load with a few games in the stretch and we thought we would take him off at half time."
Jota has since missed first-team training with the Celtic squad on Monday morning ahead of their clash with Leipzig at Parkhead, and Postecoglou is not prepared to risk the Portugal Under-21 international if he is not fully fit.
Speaking at a press conference, Postecoglou said: "It comes down to whether we think he can play or not. With all the players, they are all important in different ways.
"With the short turnaround it's not unusual for someone not to be right the day before a game when we've got such a quick turnaround.
"It's just about whether he's right or not. If he's right we'll play him - if not he'll miss out."
Jota has been a standout performer for the Hoops so far this season, scoring five goals and registering five assists in 12 games across all competitions, including a strike in the 3-1 defeat at Leipzig last week.
Celtic are already having to cope without captain Callum McGregor, who is ruled out until after the World Cup with a knee injury, while Carl Starfelt is also recovering from a knee issue of his own, but he could return before the end of the month.
Despite the potential absence of three first-team players, the Hoops were provided with a double injury boost on Monday as David Turnbull and Yosuke Ideguchi were both spotted training with their teammates at Lennoxtown.
Turnbull missed the win over St Johnstone due to tonsillitis, while Ideguchi - who has not been selected in Celtic's Champions League squad - is yet to play this season since sustaining a knee problem in training over the summer.
Celtic currently sit rock bottom of Group F with just one point from three games at the halfway stage, but a victory against their German counterparts on Tuesday could propel them back into contention for a place in the Champions League knockout rounds.
Postecoglou feels that there were positives to take from the defeat against Leipzig last week and believes his side "can hurt" the Bundesliga club in the return fixture on Tuesday.
"I think you saw last week for most of the game if was pretty evenly matches up until they scored the second goal," the 57-year-old added. "Chances were fairly even with both teams, we had similar types of chances with quick transition movements.
"They've definitely got some strengths that we've got to be wary of, but I think we showed enough last week that we also have ways that he can hurt them as well."
Celtic's only win in three meetings against Leipzig came on home soil in November 2018 when they secured a 2-1 victory in the Europa League group stage.