The Russian has looked pretty solid so far at the ATP Finals, winning two matches and dropping one. He lost to Carlos Alcaraz in the final match of the round-robin stage, which was a must-win scenario for the Spaniard while it mattered little to Medvedev.
Sinner went undefeated, winning the match he didn't have to win and securing that Novak Djokovic advanced. It was an interesting match against Rune, one in which Sinner complained about some back issues, so that's a thing to watch out for.
When it comes to the matchup, it's a pretty good one for the Italian. He actually played Medvedev twice in recent weeks and beat him twice. Both of those were finals as well, so it wasn't a match Medvedev cared very little for.
The head-to-head currently sits at 6-2 for Medvedev, which shows how lopsided this one was until recently. Sinner couldn't do anything against the Russian up until the China Open, where he bested him in the final.
He also did the same thing in Vienna, which shows that he's been peaking in recent weeks. He'll now take him on home soil, where many hope he wins again.
There is a pretty solid chance that Sinner actually wins that match because the matchup has trended toward his direction. The overwhelming baseline play becomes too much for even Medvedev to handle, which speaks volumes.
The Russian basically doesn't get flustered against anybody, but he does do that against Sinner. Despite the most recent wins, it's still a pretty close matchup, so expect this one to go to three sets. Even so, I favour Sinner to win because of the crowd. That's it.
Prediction: Jannik Sinner to win in three sets.