Ronaldo scored but could not prevent United from losing their Champions League opener
The striker knocked over the steward after skewing an effort in the warm-up into her at some force.
Ronaldo, along with medical staff, immediately checked on her well-being, before presenting a now recovered and happy steward a shirt at the Wankdorf Stadium.
The Portuguese made his Champions League return for Manchester United after his summer re-signing at the club.
He was more accurate after the game had begun, hitting the target to put Ole Gunnar Solskjaer’s side ahead having been found delectably by Bruno Fernandes 13 minutes into the Group F fixture.
However Ronaldo was substituted with nearly 20 minutes left having been later denied a penalty.
Unido, down to ten players after Aaron Wan-Bissaka’s first-half sending off, then ceded victory after an error from Jesse Lingard allowed Jordan Siebatcheu to score a dramatic stoppage-time winner.
“The game had gone 70-odd minutes, they had been running a lot both Saturday and today, the astro turf takes it toll as well,” Solskjaer explained of his decision to take off both Ronaldo and Fernandes after 70 minutos.
“We wanted Nemanja [Matic]’s experience to keep hold of the ball and Jesse’s legs.”
“[Ronaldo]’s exceptional but we have to look after him and it felt like the right moment to take him off.
“You can never be surprised by the man,” Solskjaer elaborated on his striker’s performance. “He scored another goal, he should have had a penalty and sending off the other way.”