Anyone think it is physical decline with him? Like 28 years old physical decline

We've seen it before with Brazilian players, but usually they are the lolzilian type.
He seems to really struggle getting up and down the field in a lot of games these past two seasons. I'm not going to judge players too harshly in this current climate, they all look fucked, but he has big spells in the season where he seems to be pacing himself. It's going to be be different as a 23 year old player than a 28/29 year old, you do things a bit smarter and less pointless running, but to me it seems like his legs have gone a bit.
Maybe he's playing through little injuries all the time. I often think that with Pjanic, that he seems like he is more withdrawn in a lot of games than he should be. Obviously we look at players and presume that if they are playing they are fit to play, like they are robots of sort, but we don't really have an idea of how fit they really are. With our injury record and choice of players it really wouldn't surprise me if we see this a lot at Juve as well as other teams.