The 28-year-old only signed from the Gunners last August but could be tempted by a return to the Premier League.
Newcastle United risk a Premier League fine unless a dispute over players' bonuses is resolved before their opening day fixture with Tottenham Hotspur.
The Newcastle manager said he and his backroom team have been ready to strike in the summer transfer window for months.
"You have to be very self-confident in that you are criticising Mike Ashley with what you are saying".
Speaking to reporters (via the Evening Chronicle) after Newcastle's poor 4-0 friendly defeat to Braga, Benitez told of his frustrations at the club heading into the new campaign.
Now a tough early-season fixture list means it will be hard to muster a good start.
"We have to realise we can't make these mistakes".
He was asked if he was hinting at the player recruitment at the club, to which he said: "Everything". The players have no problem with the media, but it's a way of letting people know they're unhappy.
"You're a very fearless man if you go out and criticise the owners, which to be fair is what he's doing", The former England boss told talkSPORT.
He has not been involved with the Reds' first team for most of pre-season, recovering from blisters after an early game and missing the U.S. tour as a result.