So, we're not giving you live text updates from this match - that's the bad news.
The good news is you have no excuse not to listen to ball-by-ball coverage by our BBC Radio 5 Live Sports Extra team at the O2 Arena instead.
Click the audio tab to tune in. We're sure Rafa Nadal will be...
That's because Nadal can still qualify for the semi-finals, as can Alexander Zverev, but Rafa needs the already-eliminated Medvedev to do him a favour.
Here are the possible scenarios for Saturday's semi-finals:
- If Medvedev beats Zverev, Nadal faces Federer and Tsitsipas plays Thiem
- If Zverev beats Medvedev, Tsitsipas faces Federer and Zverev plays Thiem