Andy Murray’s straight-sets win over Milos Raonic on Tuesday in London sets up a colossal and heavily anticipated matchup between Federer and Murray on Thursday, but the undercard, featuring David Ferrer, who replaces Milos Raonic, and Kei Nishikori, is important as well.

More London: Murray Takes Down Raonic | Federer Stays Undefeated

According the to the ATP World Tour Finals official website, there are seven different scenarios that we could encounter on Thursday. Fans of Roger Federer will be delighted to know that of the seven scenarios there are six in which Federer would qualify and another where he would be involved in a tiebreaker dependent upon games won.

Update: With the Addition of David Ferrer in today's play, the ATP has updated the scenarios as follows:

1) Regardless of score, if FEDERER defeats MURRAY and NISHIKORI defeats FERRER, then FEDERER wins the group and NISHIKORI qualifies 2nd.

2) Regardless of score, if FEDERER defeats MURRAY and FERRER defeats NISHIKORI, then FEDERER wins the group and NISHIKORI qualifies 2nd.

3) Regardless of score, if MURRAY defeats FEDERER and FERRER defeats NISHIKORI, then MURRAY wins the group and FEDERER qualifies 2nd.

4) If MURRAY defeats FEDERER in 2 sets and NISHIKORI defeats FERRER in 2 sets, then FERRER is eliminated and order of remaining players is determined by % of games won.

5) If MURRAY defeats FEDERER in 2 sets and NISHIKORI defeats FERRER in 3 sets, then MURRAY wins the group and FEDERER qualifies 2nd.

6) If MURRAY defeats FEDERER in 3 sets and NISHIKORI defeats FERRER in 2 sets, then FEDERER wins the group and NISHIKORI qualifies 2nd.

7) If MURRAY defeats FEDERER in 3 sets and NISHIKORI defeats FERRER in 3 sets, then FEDERER wins the group and NISHIKORI qualifies 2nd.