Cristiano Ronaldo was left furious with some decisions during the first half of the Champions League tie with Atletico Madrid and was spotted remonstrating with the officials at half-time.
Joao Felix gave the hosts the lead in the Spanish capital before Anthony Elanga equalised with just ten minutes remaining to leave the tie delicately poised for next month's second leg.
It was a frustrating game for Ronaldo, who was unable to provide a deciding impact and saw his every touch jeered by the home support due to his long allegiance with arch-rivals Real Madrid.
And Ronaldo was not happy with the decision making from the officials in the first period of the game, expressing his frustrations to the referee at the interval.
Diego Simeone's side made some fiery tackles in the opening 45 minutes of the match but were shown just one yellow card, which was issued to midfielder Marcos Llorente for a challenge on Harry Maguire.
That prompted Ronaldo to approach referee Ovidiu Hategan as the two sides returned to the dressing rooms at half-time, gesturing for him to reach into his pocket more often.
One of the first-half challenges not resulting in a booking was a cynical foul on the halfway line to prevent a United counter-attack, which left the Portugal international clutching his leg.
Further bookings were shown in the second half following Ronaldo's frustrated discussion, with Hector Herrera, Jose Maria Gimenez and Reinildo Mandava all issued a yellow card.
United were the side with the most bookings during the game, however, after picking up five - with Alex Telles, Luke Shaw, Victor Lindelof, Fred and Marcus Rashford all having their names taken.
The second-leg tie between the two teams will be played at Old Trafford on March 15.
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