Federer struggled to find his rhythm in his opening match on Sunday as he lost in straight sets to Kei Nishikori in a match that saw him register 34 unforced errors.
The Swiss was visibly frustrated throughout the match and was given a warning by the umpire for hitting the ball into the stands so he is not his usual calm self at the moment.
Federer has voiced his concern about the speed of the court and has stated that his preparation has not been ideal for the event; he has practised on the outside courts and also at Queens and Wimbledon which seems to have thrown him off his game.
Thiem put in a battling performance on Sunday but was ultimately unable to penetrate Kevin Anderson's serve as he went down 3-6, 6-7.
Having failed to get out of the round-robin stage in his previous two appearances at the season-ending finals, Thiem will almost certainly need to win here to keep alive his hopes of improving on that record.
The Austrian is one of the few players with a winning head-to-head record against Federer, although the pair have surprisingly only met on three occasions in the past.
This promises to be an intriguing match-up between two men desperate to atone for defeats in their respective openers. On the basis of those matches alone, it would be tempting to back Thiem here given that he wasn't as below-par as Federer was. However, a repeat performance from the six-time winner seems unlikely and we should see him come out firing here.
Thiem has proven in the past that he is not overawed by playing the Grand Slam champion - as shown by his winning head-to-head record - and he is decent shout to nick a set, but a determined Federer is favoured to take the match and keep alive his hopes. Federer in three sets.