The Croatian was unaware of the bid until he found out through his agent, with the Saints immediately rejecting the offer without consulting their defender.
The south coast club have already lost Rickie Lambert, Luke Shaw and Adam Lallana this summer along with boss Mauricio Pochettino and so are doing all they can to prevent an exodus.
Lovren though is furious at being kept at the club against his will and claims he no longer has anything to do with Southampton.
“Liverpool made an offer, and the club didn’t report it to me. Even after that, about the new Liverpool deals. It was not fair,” Lovren told Croatian paper Jutarnji List.
“I learned about the offer from other people, it really hit me and I realised that I no longer have anything to do with Southampton. Liverpool has sent an offer of £20million, and they paid me £9million, they would have made more than twice.
“At this point I do not know what I will do and I do not like that. And indeed it was unbelievable that a few days ago they agreed to an offer of £20million.
It was in the morning and in the afternoon they said that I’m not on sale? Frankly, my head is in Liverpool. Anyway, I sent a letter to the club where I said all this I told you.”