Arsene Wenger has warned Arsenal's rivals at the top of the Premier League they can forget about taking any of his players on loan.
The Arsenal boss admitted he blocked a loan move for right-back Mathieu Debuchy to Manchester United last month, and suggested he would never lend one of his players to a direct competitor in the league.
"I hope that's not surprising to you, if Man United wants to buy a player." Wenger told a press conference.
"You loan players out to clubs who do not have the resources, but not to direct opponents. There was nothing shocking in that and it's true, I stand up for that. I was surprised, yes [by United's attempts to loan Debuchy]."
Earlier this week France international Debuchy said he was "disappointed" he wasn't allowed to move to Old Trafford.
"I was disappointed, obviously," said the right-back. "If I had the chance to go to Manchester United it would have been magnificent.
"Unfortunately, it wasn't the case. I discussed it with the coach too, who said that obviously he couldn't help out a rival."
In contrast, Arsenal have benefited from other clubs' willingness to sell them their best players, having purchased goalkeeper Petr Cech and striker Danny Welbeck from Chelsea and Manchester United respectively in the last two seasons.
It has been almost four years since Wenger last sold a player to a direct rival for the Premier League title.
Robin van Persie was sold to Manchester United in 2012 for around £20m, although that move was mitigated by the fact the Dutchman had just one year remaining on his Arsenal contract and was eager to move.