In-form Russian Medvedev and Green sensation Tsitsipas go head-to-head within the season-ending occasion on Monday afternoon on the O2 Arena in London.
Despite being tipped to get pleasure from a decade on the high of the game, world quantity six Tsitsipas has by no means overwhelmed Medvedev and the pair clashed earlier this yr in Miami.
Medvedev goes into the ATP Finals in implausible kind, having received 29 of his 32 matches forward of this month’s Paris Masters and boasting a 59-18 file total in 2019.
And former British primary Henman believes Medvedev’s consistency might show important as he bids to down Tsitsipas once more and kick-start his ATP Finals marketing campaign.
‘This is going to be a really interesting match,’ Henman instructed BBC Sport. ‘Medvedev is the one participant who has taken lots of people without warning this yr.
‘It’s not simply been his stage of play, however the constantly has been very good. He’s received a whole lot of tournaments, he’s been in last after last and he’s received large tournaments too.
‘I would give him the slight edge there but it’s going to be fascinating to observe.’
In the opening match of the 2019 ATP Finals, final yr’s runner-up and world quantity two Novak Djokovic crushed debutant Matteo Berrettini 6-2 6-1.
Reacting to the one-sided win, Djokovic stated: ‘It feels nice to be again in London. Earlier this yr I had a terrific keep in London, and performed properly at Wimbledon.
‘Over the years I have played well in this arena and this event, which holds elite eight players. It’s a really profitable event and I’ve loved it very a lot.
‘I managed to play solidly throughout the match. I have been enjoying the conditions and this court for many, many years. Hopefully it continues this week.’