According to the Guardian, the 30-year-old had refused to play for Sevilla in their first-leg Champions League play-off against Braga in Portugal, as he was trying to avoid becoming cup-tied and risking a transfer to Arsenal.
Sevilla's coach, Antonio Alvarez, said: "I didn't like the fact that Squillaci didn't want to play but the circumstances turned out that way."
Apparently the defender had been named in the lineup, only to be suddenly withdrawn, said Sevilla defender Julien Escude.
"When the coach gave his team talk, Sebastien was starting," Escudé said. "Then, I do not know what happened, with the coach or the sporting director, but there was a change in the line-up.
"Later, we knew Sebastien refused to play. I was surprised."
Squillaci himself was unperturbed by any accusations, and said that once he knew Arsenal boss Arsene Wenger was interested in him, the decision to leave La Liga for the Premier League was easy.