The Uruguay legend signed a one-year contract at Old Trafford on transfer deadline day, having left French champions PSG at the end of last season.
Cavani won six Ligue 1 titles and scored 200 goals in Paris and will hope for more success at Manchester United under Ole Gunnar Solskjaer.
A number of clubs were interested in signing free agent Cavani this summer but the striker says a conversation with Herrara helped make up his mind.
‘Yes, I spoke with Ander a lot, as well as other team-mates, like Angel Di Maria, who I was also with at Paris,’ Cavani said.
‘It was genuinely getting to the last minute and I called Ander to have a chat.
‘I have a lot of admiration for Ander, for the kind of person he is and I had the feeling that his words were going to help me out, by telling me a bit about what it was like at United.
‘And so, yes, it’s true that after I’d finished talking with Ander, we came to an agreement here with the club.
‘I hadn’t known Ander for too long, but we formed and enjoyed a close friendship during that time at PSG, and today we are still very good mates.’
Herrera made close to 200 appearances for Manchester United and helped the club win the Europa League, FA Cup and EFL Cup before joining PSG in 2019.
‘I’ve worked really hard during the time off and I feel eager to compete and represent this incredible club.
‘I have played in front of some of the most passionate supporters in football during my career and I know that it will be the same in Manchester.
‘I cannot wait to experience the Old Trafford atmosphere, when it is safe for the fans to return.
‘I look forward to continuing to write my little story inside the book of football and I know that’s why my focus has to remain the same as always – work, work, work.
‘I have had a conversation with the manager and this has increased my desire to wear this beautiful shirt.’