Manchester United manager Jose Mourinho bombarded Paul Pogba with calls and text messages as he battled to secure a return to Old Trafford for the France midfielder.
Pogba rejoined United in a world-record move from Juventus last month despite reported interest from Real Madrid.
Mourinho told Goal there was "another big club" in the running for Pogba, which meant the Portuguese felt the need to wage a relentless phone campaign.
"Oh, it was hard to convince him," he said. "I had many [conversations] on the phone, lots of SMS.
"I think he was getting one in the morning from the manager from another big club and one in the afternoon from myself.
"I had to try hard to convince him to choose us instead of the other one."
The Champions League gets underway in United's absence this week, while their 100 per cent start to the Premier League season was brought crashing to earth by a 2-1 defeat against local rivals Manchester City on Saturday.
Nevertheless, Mourinho's early days with the 20-time English champions have left him feeling optimistic about the future.
"I have a very positive feeling," he said. "Rome was not built in one day and a football team is probably more difficult to build than Rome was!
"The feeling is that they want to work for me, they have the same level of ambition and commitment that I have and step by step, by a tactical and mental point of view, I have great feelings with the answers they are giving. So yes, I am very positive."