Giovanni van Bronckhorst reckons keeper Allan McGregor was "unsighted" for the RB Leipzig goal which downed Rangers in Germany.
A sturdy Ibrox rearguard was finally beaten by a spectacular Angelino volley to give the Bundesliga side a slender Europa League semi-final advantage.
The full-back smashed home from the edge of the box but pictures showed Leipzig players in an offside position in front of McGregor as the ball fizzed through a ruck of bodies.
And Van Bronckhorst, whose team host the return leg at Ibrox next week, believes the shot-stopper's view was obstructed after viewing the footage post-match.
"After the game, we saw some images that Allan (McGregor) appeared to be unsighted for the goal, it was a great strike.
"Angelino hit the ball almost perfectly but you want your goalkeeper to have a chance. I think they checked it with VAR and watched the positions of those players.
"But it's a discussion after the game when the goal has counted.
"We know our crowd will give us a lot of energy and we will be prepared for the return leg.
"We still have a shot at a European final, this shows the excellent performances of our players in Euopre. We have a shot next week to give it our all and our aim is to reach the final."
Rangers ' attention now turns to a derby showdown with Celtic on Sunday in the knowledge that a win for their rivals will effectively return the Premiership title to Parkhead.
Van Bronckhorst has suggested he may not consider resting players for the Leipzig return as he insisted the defending champions will go "all out" to peg the league leaders back.
He said: "We will do our recovery session today and then fly back. Today is very important to recover well and make our plans for Sunday, it is still too early to tell who will play or not.
"Our focus is now on Celtic, we will recover and prepare for the game on Sunday. The belief is there, we will go there to get a good result.
"Yesterday the approach was to bring a good result back to Ibrox, Sunday we have to go all out and do everything for the win.
"My objective is to have my players well prepared mentally and physically. I know my players will do everything on Sunday to get a good result, this is what they have continued to do through a hectic schedule."
