Anderson served superbly in his opening match against Dominic Thiem; he won 91% of his first serve points and did not face a single break point on his way to a 6-3, 7-6 victory.
The world number six has become a highly consistent player on the men's tour in recent years and his form coming into the tournament was good so confidence is not an issue at the moment.
This will be the fourth time that the South African has faced Nishikori on indoor hard courts this year and he has had the better of his Japanese opponent on two of those occasions, although he did lose their most recent meeting in Paris.
Nishikori claimed the scalp of Roger Federer in his opening match on Sunday which will have given him great belief although it has to be said he benefitted from an uncharacteristically error-strewn display from his opponent.
Nishikori himself struggled at times during that match and made six winners compared to 22 unforced errors but he will pleased to have got the win under his belt whilst not playing at his best.
The world number nine's recent straight-sets victory over Anderson in Paris will be fresh in his mind and he has the edge overall in career meetings as he looks to make it two wins from two.
Two wins in the round-robin stage is often enough to qualify for the semi-finals so Anderson and Nishikori will know the importance of this clash after they were both victorious in the opening matches on Sunday.
These two are very evenly matched despite their contrasting styles, so a close encounter is expected. If Anderson can serve as well as he did against Thiem he will give himself opportunites but Nishikori is a renowned returner and will look to prolong points as much as possible. His recent victory over the South African just gives him the edge although it is unlikely to be a straight-sets affair. Nishikori in three sets.