The 2009 champion made a decision to skip the red-clay courts of Roland Garros to focus on upcoming grass-court and hard-court tournaments. Williams is pregnant and due in the fall, with plans to return to the tour in 2018.
Now they have agreed to work together at the French Open on a temporary basis.
Locally, McMurray native Alison Riske awaits her first-round draw, which will be revealed today.
Agassi, who was in Paris for a sponsor commitment, was on court with Djokovic on Thursday for two practice sessions, Djokovic said.
Last year's beaten finalist, who will start the tournament as top seed for the first time, has won both his previous encounters with the world number 85 - though has never faced him on clay.
Defending champion Djokovic, whose win in 2016 completed a career grand slam, opens against Marcel Granollers of Spain on May 28. Top-ranked Angelique Kerber will take on Ekaterina Makarova to start her bid. I need to try and enjoy this period nearly because the more frustrated you get, it doesn't help.
"Rafa, next to Roger (Federer), has been the best player this year in terms of results", Djokovic said.
Falls police investigating shooting incident on Whitney Avenue
Police say there were two shootings and a stabbing amid two large fights, all of them occurring between 2 p.m. and 6 p.m. According to detectives, a bullet hole was found in the front of the house and a slug was found on the floor inside.
Which woman will step up?
Two-time French Open victor Maria Sharapova is missing because tournament officials denied the 30-year-old Russian a wild-card entry following her return from a 15-month doping ban in April.
Title favourite Simona Halep was rated only 50-50 on Wednesday after damaging ankle ligaments and will give an update on her fitness on Friday. Although the Romanian fell short in the final of the Italian Open against Elina Svitolina, she has showcased excellent consistency on clay, winning the Madrid Open earlier this month.
But the 30-year-old Scot is confident he can once again overcome adversity. Stan Wawrinka is also expected in the draw, the Swiss having won the title in 2015 at Djokovic's expense.
Potential challenges could come from a new generation of big hitters such as rising Austrian Dominic Thiem and Germany's new wunderkind Alexander Zverev, but Nadal looks in the mood to regain his Parisian throne.
The tournament will also see two-time Wimbledon champion Petra Kvitova making her comeback less than six months after she was stabbed during an attack at home in the Czech Republic.
The French Open tennis tounament starts.
Britain's other representatives in the main draw are Kyle Edmund, who plays the Portuguese Gastão Elias, Dan Evans, who might struggle to reproduce the heroics on clay that he showed on the hard court of Flushing Meadows in a competitive four-setter against Tommy Robredo in 2013, and Aljaz Bedene, who has a good chance against the American, Ryan Harrison.
"Mladenovic has a had a great claycourt season and I think she will not be intimidated paying in Paris at all". The two best players in the sport aren't in Paris, injuries are affecting the one-time favorite and no one has pushed to the front of the pack in the lead-up to the clay-court major.