I keep reading this about Fabinho but he only turned 29 at the end of October and if I recall correctly didn’t start a WC game, whatever the issue is, it shouldn’t be his age or fitness surely?
I think some people misremember or misattribute what it was that made Fabinho an elite player in the first place. I don't think he was ever an elite typical defensive midfielder sweeping in front of the back four protecting them against the counter; his strength was subtly higher up the pitch, earlier in play: stopping a transition at source. He was elite in backing up the press, reading where the opposition were about to transition, winning second balls, recycling and picking out a clever pass. He's definitely lost (age? injury? illness?) a touch of athleticism necessary to make that initial adjustment, to close and win the ball with a lunge. He's never been quick over a distance, and it was never really the core of his game to cover in behind fullbacks.
It gives him, or us, a problem I think: because if we're not high intensity relentlessly pressing, I don't think he's the same player, even if he regains form and a bit of the missing athleticism. If we need a covering, sweeping DM, there are players with greater pace and stamina who can do that job more effectively.