Manchester City were offered the chance to buy Paul Pogba and Henrikh Mkhitaryan from Manchester United in January, says manager Pep Guardiola.
Guardiola said the pair's agent, Mino Raiola, contacted him and told him the midfielders were available.
Pogba, who joined United for a then world record £89m in 2016, stayed at United as Mkhitaryan joined Arsenal.
Raiola told BBC Sport he did not speak to Guardiola but did not deny telling City of the players' availability.
A senior United source said they would not have sold Pogba in January, and they would not have sold him or Mkhitaryan to City.
In his news conference before Saturday's Manchester derby at Etihad Stadium – when City will win the Premier League if they beat their rivals – Guardiola was asked to comment on reports that Raiola called him "a coward" and a "dog" for the way he treats people.
Guardiola said: "Two months ago he offered me Mkhitaryan and Pogba to play with us.
"Comparing [me to] a dog is bad – it's not good. He has to respect the dogs."
'I never spoke to Guardiola'
Pogba was a regular in the United team since rejoining the club from Juventus in August 2016, but was left out of United's starting line-up for both legs of their Champions League last-16 defeat by Sevilla in February and March 2018.
Spaniard Guardiola refused to say whether he was interested in Pogba but said the 25-year-old France international "is an exceptional player, a top, top player".
Raiola, 50, is agent to several star players, including former Sweden and United striker Zlatan Ibrahimovic.
The Italian told the BBC he is a huge admirer of Guardiola but said: "I never spoke to Pep Guardiola. I would not speak to him about players; I would speak to Manchester City.
"They are a fantastic club with a fantastic manager."
Armenia international Mkhitaryan, 29, joined Arsenal in the January transfer window as part of a swap deal that saw Alexis Sanchez move in the opposite direction.
'We don't have the money to buy Pogba'
Guardiola said there was "no way" a deal for Pogba would be possible.
"We don't have the money to buy Pogba because he is so expensive," he said.
Raiola fell out with Guardiola when he was manager of Barcelona over his treatment of Ibrahimovic, who criticised him in his autobiography.
Ibrahimovic accused Guardiola of "buying a Ferrari" but driving it like "a Fiat".