Coverage for the ABN AMRO World Tennis Tournament begins Monday on Tennis Channel & Tennis Channel Plus.
Roger Federer's wild card entry into Rotterdam next week will give him a shot at the No. 1 ranking currently held by Rafael Nadal.
Along with potentially extending Federer's record 302 weeks in the top spot, it also brings into play 33-year-old Andre Agassi's record as the oldest player to hold the men's No. 1 ranking.
Federer had not been scheduled to play the indoor ATP 500 event, but organizers announced his participation just days before play begins. He has not played the tournament since 2012, but his relatively undemanding journey to the Australian Open title, along with the opening for No. 1, might have helped prompt him to join the field.
Federer would reach No. 1 if he can get to the semifinals or further in Rotterdam, the ATP has confirmed, while Nadal is not scheduled to return to play until Acapulco in three weeks.
Winning the title would allow Federer to stay No. 1 following Acapulco. Otherwise, Nadal could return to the top ranking by winning the 500 event in Acapulco, unless Federer also plays the 500 Dubai tournament the same week. Federer is not currently scheduled to play Dubai, but he had spoken to organizers about playing the event and has not said whether his participation in Rotterdam means he will not play Dubai.
Nadal is defending 300 points as the finalist in Acapulco, while Federer would drop 45 points in not playing Dubai.
Nadal should also be positioned to stay or get back to No. 1 at Indian Wells, which begins the following week. The Spaniard, who retired with a leg injury at the Australian Open, has said he plans to return at Acapulco.
The women's No. 1 ranking could also change hands again next week, with Simona Halep having an opportunity to unseat Caroline Wozniacki with a good showing in Doha.