"For the last two years they have not been able to beat us, today they will think they have a chance".
Arsenal dominated PSG in an exciting preview of what could be this season.
The Red Devils were beaten 4-1 by Liverpool and Mourinho said afterwards that Martial should have re-joined the squad in time to play against Liverpool.
Klopp will no doubt make it clear who is Liverpool's penalty taker ahead of their Premier League campaign.
Mourinho added: "I think too much holiday for him".
Liverpool, in contrast, is still a football club in enveloped in optimism. He talked of the seven years since United's Champions League final appearance, during which they could manage no better than a solitary quarter-final.
Klopp inspires those around him and he even met up with fans two nights before the game at a supporters run event in Detroit.
Mo Salah was a threat throughout and he was eventually brought down in the 26th minute inside the area.
Liverpool, who dropped off after a lively start, took the lead when Mohamed Salah was awarded a penalty following a challenge from Demetri Mitchell.
Mourinho said that Matic has undergone surgery and will miss the start of the season Glyn Kirk AFP
United were without new signing Fred during the win but Mourinho hopes that the Brazilian will be able to improve his side's attack this season with his range of short passing.
The score was 1-1 at half-time, though Grant was again needed to save from Virgil Van Dijk after 43 minutes. "His condition was not good when he was back", he said.
Both debutant Shaqiri and Sturridge were excellent, as was Saido Mane.
Ojo's goal came on a second penalty kick for Liverpool, and the always-outspoken Mourinho had some choice words about the officiating.
Xherdan Shaqiri put a stamp on his Liverpool debut with a spectacular bicycle-kick goal to round out the scoring in the International Champions Cup match in front of a crowd of 101,000. "That is not normal". It helps them to understand the game.
Mourinho's mood is very different. That's not normal after four days in the club - adapting that well to the style of play. If it's not, it's not. We played over 90 minutes of really good football on a very hard pitch for both teams.
Marcus Rashford and Phil Jones will return early.
"I don't think he's a leader", Mourinho said.