The events have been impacted by the coronavirus and the decision of Roland-Garros to move back by a week.
"Djokovic, you said he was injured, right? I don't know if that was the case," Stefanos Tsitispas said.
The pair will work together starting next week in Istanbul
The Austrian hopes to make a full return at the Madrid Open in May.
Dan Evans has a bone to pick with Lorenzo Musetti.
"I just felt awful on the court overall," world No. 1 says after bowing to British No. 1 Dan Evans.
Five of the world's Top 10-ranked men play with Head.
