With Richardson in the coaching box, Raducanu made history by winning the US Open without dropping a set as an 18-year-old qualifier in 2021.
The 23-year-old is set to make her return to action in Strasbourg, 10 weeks after losing to American Amanda Anisimova in the Indian Wells third round on 8 March.
She has been granted a wildcard for the tournament as she seeks match practice before the French Open, the second Grand Slam event of the year, which begins on 24 May.
Following her absence from the tour, caused by a post-viral infection, Raducanu is set to miss out on a top-32 seeded position at Roland Garros after slipping to 37 in the world rankings.
Raducanu parted ways with Richardson after her US Open win, and has been without a permanent coach since parting ways with Francis Roig after her second-round exit from the Australian Open in January.