Though just 19, a season with the U21s would not do for the £3 million signing from Hajduk Split. Instead, Mourinho sat the young midfielder down with Emenalo and recommended he spend the season in Spain.
"When I arrived at Chelsea, Mourinho told me that the best thing for me was to play in Spain," revealed Pasalic upon joining Primera Division minnows Elche. "In the Primera, I'd have the opportunity of facing big teams like Real Madrid, Atlético or FC Barcelona."
Croatia coach Niko Kovac, having included Pasalic in his World Cup preliminary squad last summer, was delighted with the decision and has since received glowing reports of the player's progress. Croatian observers rate Pasalic the best performing 20 year-old midfielder in the La Liga and are convinced his game has benefited from the Elche move.
Pasalic, who struck 11 goals from Hajduk Split's midfield last season, has had nothing handed to him at Elche, despite the high praise from president José Sepulcre upon his arrival: "We have signed the future of world football."
Instead, he's had to fight to win over coach Fran Escribá, who hasn't been afraid to withdraw Pasalic at times from the frontline.
"Everything is fine, everything is running its course and I do not to worry about my status," assured Pasalic.
"I regularly speak with the coach and also Chelsea sporting director Michael Emenalo, who follows my games. He is happy, so I have to be pleased they are happy with me.
"The people at Elche are great, the city is beautiful, like Split, so I have quickly adapted."
Emenalo signed Pasalic with a long-term view of him becoming a genuine box-to-box midfielder. At Hajduk Split, his goalscoring quickly put him on the map, but pleasing for Chelsea's football chief, Escriba is fast developing Pasalic's defensive game.
"I'm playing as a defensive midfielder," says the youngster.
"I can't say what happens in other leagues, but here (Spain), such a position usually goes to someone far more experienced. You need to have good fitness levels and tackling power to perform well in this role."
"I would love to score my first goal here," he says. "But I know I won't get much of a chance.
"The team plays defensively. We have to fight for every point and it's difficult to push forward if you're a defensive midfielder. You're basically running the entire game just to keep the opposition away from your goal.
"Every match is a battle. There is a struggle for survival."
Along with strengthening the defensive aspects of his game, Pasalic has also added to his big-match experience, having already played at Barcelona's Nou Camp and Real Madrid at the Santiago Bernabeu. Though he finished a loser on both occasions, Pasalic treasured the chance to clash with Lionel Messi and Cristiano Ronaldo.
"When you face them 'live', it is entirely different to watching them on television," he recalls.
"The atmosphere at the Bernabeu? Something awesome! Full stands, a beautiful stadium ... Oh, I have no words."
Pasalic was also thrilled with the support he received from two senior Croatian stars.
"I did not get to play against Luka (Modric). He was still recovering (at Real).
"But we spoke briefly and he gave me some tips. Everyone knows he's a great player - but also a great man. He gave me a souvenir shirt of his."
Pasalic added: "And after the Barca game, I was able to get (Ivan) Rakitic's shirt. So I have both!"
Mementoes aside, Pasalic is showing every sign that he will be added to Mourinho's Blues squad next season.
And for Sepulcre, he knows the form Pasalic is showing could lead to a long-term relationship with Chelsea.
"Pasalic will go back to Chelsea a much better player than he was," insists the president. "Mourinho wanted him to come to Spain because he liked our project."
A project that promises to return the young Croatian to Chelsea a better all-round midfielder.