Yeah his walking around for goal number 1 especially was the thing for me. Maybe this is the defining moment as he wasn't doing it the entire game as much as people will have you believe he did. But it was a terrible look and needs to be called out on that specific moment absolutely.
Sprinting backwards, again it's never been a defining attribute for him - because he doesn't have that sprint speed. It's not lack of effort, it's lack of ability. Robbo got caught out of position loads during his prime but had that speed to get back and was able to save himself somewhat. Kyle Walker made a career from it. Mainoo for Man Utd got caught out at least twice every game last season and again this season has shown signs of it where there is a counter attack against them and he is basically jogging backwards leaving massive empty gaps in midfield. Which they have conceded a few goals from too. People have never once questioned his lack of effort, it's just that he is slow! But because Trent doesn't have massive afterburners, it's taken as lack of effort.
But that's going backwards. When the ball is in front of him, he needs to be pressing and harrying more. Absolutely. There is no hiding from that.
I think that big glare VVD gave him at the end was because his passing was poor and giving it away cheaply, not from lack of trying. he made 8 interceptions yesterday. Was that the highest in the match? You don't do that with lack of effort and 'not wanting to defend'. The tackle on Dalot in the first minute doesn't come from lack of effort or not wanting to defend.
Correct me if I'm wrong but Trent didn't make a single tackle yesterday.
Agree with the gist of your post tough. His lack of mobility, certainly in terms of quick bursts, can make him look like he doesn't care. He has never had afterburners. Recall Rashford giving him a real going over for pace early in his career. Wilfred Zaha another who loved skinning Trent.
This lack of recovery pace means that he gets done too easily.
The issue with Trent not having real pace though is this is compounded by him not sensing danger either.
Carra didn't have the former, but he did have the latter quality, as he always sensed danger so positioned himself accordingly to make it harder for an attacker to exploit his mobility issue.
Steve Bruce, again not the most mobile, but knew where to position himself (Romario was one of the very few players to give him a real doing).
Paul McGrath (especially in his later years) could barely move, he couldn't train at all as his knees were fu**ed, but his reading of the game, knowing where the danger lay, often saw him come out on top, and there was no better display of this vs R.Baggio, Signori and co. at Giants Stadium in the '94 World Cup.
Against Fulham, Trent switched off twice, and only sensed danger when it was too late (ie. when the pass was made out to the wide player he was meant to be tracking, with his attempt to block the cross coming too late before they scored). This waking up late to danger is a common theme of his. For the opener yesterday, so passive, like it was a kick about, and only when the pass was put through to the goalscorer did Trent wake up and make a run, but by then, too late, again.
Physically: Not quick enough over short bursts nor to make a recovery tackle
Mentally: Not switched on to sense danger until it's too late.
It's this combination that makes Trent a pisspoor defensive player, and one who needs protection by the midfielders as happened under JĂŒrgen. He has not been afforded this under Slot so more of the onus is on him to do his job, but he lacks those key characteristics to do so effectively. It's for this reason I dont think he is a full back, but is playing that position on the field as it's there where he gets time and space to allow him make those extraordinary passes that he has in his locker.