He visited a specialist in Spain over the international break to address the issue, but has missed Spurs’ last two games, including Monday’s 3-1 victory over Coventry.
De Zerbi has now, though, offered a mixed update on Spurs’ first-choice full backs, saying: “Pedro is back, [Udogie] is not available.
“With the medical staff, we are trying to find the best way for him. But after Manchester United, I have not worked with him, and it is a problem. We are lucky because in the same position we have solutions.”
Omar Marmoush and Andy Robertson are also fit and available despite appearing to struggle with injuries before being replaced in the second-half against Coventry.
At the time, De Zerbi said their issues were “nothing important” and he said the same ahead of Saturday’s visit to Stamford Bridge.
Dejan Kulusevski made his first competitive appearance in 526 days against Coventry, while James Maddison made his first competitive start since May 2025.
The pair have endured incredibly tough periods on the sidelines, but De Zerbi has confirmed both players are doubts to face Chelsea despite coming through the Coventry game unscathed.
De Zerbi said: "I don't know, because in the first three days Maddison didn't work with us, I don't know if he's ready for tomorrow. We can play also with Mathys Tel, we can play with Marmoush, we can play with Gallagher, or we have more solutions considering Pedro Porro can play.
"Like I said many times, I don't want to take risks, because if you analyse this period of European football, you can see many injuries, not [just] for Tottenham, for everyone. So if I can, I don't want to take risks to lose many players for many games.
"Kulusevski also (I don't know if he is ready for tomorrow). Kulusevski worked well, but on the first day (after Coventry) he stayed individual."
Spurs are looking for just their second league win of the season when they take on bitter rivals Chelsea in a fixture they have historically struggled to win.