Celtic forward Nicolas Kuhn was left with a bloody nose after taking an elbow to the face during the Old Firm on Thursday.
The 25-year-old was caught by the flailing arm of Rangers defender Jefte while battling for the ball during the closing stages of the first half. He immediately hit the deck with blood pouring down his face and was treated on the pitch for several minutes.
It appeared to be an unintentional elbow from Jefte, who received a yellow card for his involvement. The incident was checked over by VAR but no further action was taken, with the Rangers man avoiding a red card for violent conduct.
Chris Sutton, a former Celtic player, was on punditry duties for Sky Sports and said: "He catches him nastily, I think it is an accident."
Main commentator Ian Crocker added: "It's confirmed as a reckless use of the arm, so just a yellow card from the VAR today."
Rangers were leading at the time of the incident, with the hosts making a fast start in the first Old Firm of the new year. Ianis Hagi scored the opening goal after just seven minutes, finding the bottom corner with a first-time effort from outside the box.
Philippe Clement's side were dominant in the first half, with Celtic failing to register a shot on target until just before the break. Tensions flared up at the interval with Nico Raskin and Callum McGregor clashing on the pitch after the whistle had gone.
Raskin was shown a yellow card but Celtic skipper McGregor, who was already on a booking, went unpunished.
Reflecting on Celtic's dull display in the opening 45 minutes, Sutton said: "I can't remember too many times this season where Celtic have been this flat in a first half. They have not got going."
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Neil Lennon, who had two spells in charge of the Parkhead club, added: "Celtic are miles off it, the distances between each other. Brendan [Rodgers] will be having really strong words."
Rangers legend Kris Boyd, meanwhile, was pleased with his former side's display but urged caution heading into the second half.
"You need to get that second goal," he said. "Celtic have been miles off it. Credit to Rangers, they pressed and stopped them."
In the second half, Celtic were denied an equaliser when Kyogo's acrobatic finish was ruled out for offside. Minutes later, Rangers went agonisingly close to a killer second goal with Vaclav Cerny rattling the woodwork from inside the area.
They eventually doubled their advantage through Robin Propper, who stabbed the ball home from close range after Celtic failed to clear their lines following a corner.