Rojo played a full game against Bolivia in the draining altitude of La Paz while Valencia also featured for 90 minutes against Colombia in Quito and Mourinho believes counterpart Tony Pulis will have an advantage come Saturday, even if his claim West Brom only had one player away on international duty was wrong.
“I watched Valencia’s match yesterday in Ecuador, Marcos Rojo in Bolivia, but they don’t arrive until Thursday afternoon,” Mourinho said.
“If you compare our situation with our opponents, West Bromwich Albion, only one player on international duty. They had time to work, time to rest and prepare. It’s going to be hard.”
Bastian Schweinsteiger meanwhile travelled to the US on Wednesday to complete his move from United to MLS side Chicago Fire on a free transfer, despite having more than a year to run on his Old Trafford deal.
The former Germany captain said he did not get a chance to say goodbye to team-mates. “It was not so easy because the decision was a bit late so I couldn’t say a proper goodbye to the team” he said.