Roger Federer is expected to play in his home tournament at the Swiss Indoors in October.
Federer is a record 10-time winner at the event in Basel, having not lost a match there since 2013, and won the last of his 103 titles there in 2019.
The 20-time Grand Slam champion has not played since Wimbledon in July 2021 and underwent knee surgery later that year.
The 40-year-old is also planning to play for Team Europe in the Laver Cup event in London in September.
A tournament statement said Federer had entered under his protected ATP ranking of nine.
He will play his opening match on Tuesday, 25 October.
The tournament, which will be staged for the first time since 2019 after cancellations caused by the Covid-19 pandemic, will start on 24 October.