Martin O'Neill has responded to Paolo Di Canio by insisting that it was a player he signed that helped Sunderland survive in the Premier League last season.
The pair have engaged in a war of words of late, with the Republic of Ireland boss throwing the first shot by calling the Italian a "managerial charlatan".
Di Canio, who succeeded the 61-year-old at the Stadium of Light in March, hit back by claiming that his predecessor spent "£40m to be a top 10 club and then sees the club sink into the relegation zone".
However, O'Neill has disputed that figure, although he did state that it was his £15m purchase of Steven Fletcher that ultimately saved the Black Cats.
"At the end of the day, it's hardly worth it," O'Neill told reporters following Ireland's 3-0 win over Latvia.
"You would have to go and check, but I don't think Sunderland would concur with his £40m for a start. Even Sunderland wouldn't do that.
"Seriously, one of those people he's talking about (Steven Fletcher) actually, his goals helped Sunderland stay in the league, and [Simon] Mignolet, they got £10m for."
Fletcher scored 11 goals in 28 games last season.
