Jose Mourinho has re-ignited his war of words with old rival Arsene Wenger, claiming he is preparing Arsenal for failure.
Wenger signed a new two-year contract after winning the FA Cup against Chelsea in May, taking his stay in North London to 23 years if he sees the deal through.
Shortly before the cup success, Wenger finally managed his first ever competitive victory over Mourinho, with Arsenal beating Manchester United 2-0 thanks to goals from Danny Welbeck and Granit Xhaka.
Mourinho famously called the Frenchman a "specialist in failure" a couple of years ago, and they almost came to blows on the touchline in 2015 during Mourinho's final season at Chelsea.
And now, the Portuguese has seemingly taken a swipe at the Arsenal manager, implying that the Gunners will not be a top club when he eventually departs.
He claims that his impact on a club lasts long after he leaves the job. Since Mourinho left Real Madrid, they have won the Champions League three times, and Chelsea won the Premier League title and reached the FA Cup final the season after he left.
"I prepare clubs for success. I think I prepare clubs in a way where, when I leave, the new manager arrives at a top club. And that is not short-term even if you leave," he commented.
"If you're in a club one or two years - or any job - if you leave a structure to be even more successful without you than with you, that's not short-term. That's long-term.
"Short-term can be the guy that is at one club 10 to 20 years and when you leave the club, it's ready for failure."
Though clearly a dig at Wenger, there is some suggestion that his comment relates to Sir Alex Ferguson.
United haven't won the Premier League since 'Fergie' retired in 2013, with David Moyes failing with the players he left behind, and van Gaal deciding to overhaul almost the entire squad.
Arsenal's structure appears to be falling apart, with Alexis Sanchez available on a pre-contract deal to foreign clubs in January, along with Mesut Ozil.
Alex Oxlade-Chamberlain left to join rivals Liverpool on transfer deadline day, and with the Gunners losing their two opening away fixtures in the league without scoring a goal, they are in crisis.
Mourinho's tenure at Old Trafford got off to a shaky start, with their difficulty to win games at Old Trafford leaving them with a sixth-placed finish.
However, the 'Special One' landed a Europa League and EFL Cup double, and there is much promise for the season ahead, as he has won the league title during his second season at every club.
Added to their nine unanswered goals and 100% record so far, with £90m man Romelu Lukaku scoring three in as many games, Mourinho certainly seems to be preparing the Red Devils for success.