I just think their main guys look a bit jaded, the likes of Alli, Eriksen and Kane play almost every game when they're available. I'm worried we're going to do the same to Salah to be honest.
We do have a quite similar player in Mané when Salah needs a rest, to be fair, who's also fairly fresh after a few injuries.
Spurs has always had a fairly thin squad. They've failed for a third season in a row to get backup for Kane. There is no other Alli in their squad and there is no other Eriksen.
Their defence is fine. But the more you fail to score goals as a top team, the more likely you'll concede a goal, as the pressure will always be on you and not the other team to win.
(I just pulled that last bit out of my arse, but it sounds sensible, right?)