Islam Slimani scored a controversial equaliser against PSG on Sunday, with Thomas Tuchel failing to comprehend why it was not disallowed.
An exasperated Thomas Tuchel accepted he no longer knows the offside rules after he was left baffled by the decision to allow Islam Slimani's Monaco equaliser to stand during Paris Saint-Germain's 3-3 draw on Sunday.
Gelson's shot found its way to the seemingly offside Slimani via a touch from Marquinhos that was deemed to be deliberate, and the on-loan Leicester City striker swept home – VAR ruling in the visitors' favour after the assistant initially ruled it out.
Tuchel was bemused by the situation.
"The third goal… I don't, I can't understand," Tuchel said in his post-match news conference. "Really, why is it not offside?
"Everybody said to me that it is the new rule. Okay - after that, I have to say that I don't understand the rules, but it doesn't help."
In a prickly response, Tuchel said: "Do you think differently, that they [Gueye and Verratti] are not complementary? Do you think I would start the two if I thought they're not complementary? Doesn't make sense right?
"For me, Marquinhos can play both positions at an unbelievable level. He is a world-class player in both positions.
"Recently we've some troubles [in defence], because Presnel [Kimpembe] was injured for a few weeks, Thilo Kehrer was injured for a long time, he's already played twice, so it was not the moment for him to play a third time, Abdou Diallo was not available and it was the first game for Thiago Silva.
"That's why we used Marquinhos, because it was the logical solution for this game, but for me, it's still possible to play with Marquinhos in midfield, because he gives the team some quality, a lot of energy and personality.
"It was necessary for me to find a solution like that [against Monaco] because my three central defenders are injured, or just got back from injuries. It was logical."