Manchester United manager Ole Gunnar Solskjaer has defended taking off Cristiano Ronaldo and Bruno Fernades towards the end of Tuesday's loss to Young Boys.
With the scores tied at 1-1, both players were substituted for Nemanja Matic and Jesse Lingard with 72 minutes on the clock.
"The game had gone 70-odd minutes," Solskjaer said. "They've both been running a lot Saturday and today.
"The astroturf takes its toll. We wanted Nemanja's experience and Jesse's legs."
Lingard eventually cost the match when his errant back-pass allowed Jordan Siebatcheu to score a simple winner.