The 29-year-old Richarlison reinforced his importance with a last-minute winner as 10-man Spurs beat Chelsea 2-1 on their pre-season tour in Sydney on Saturday.
He also scored in their 2-0 win over Auckland FC last weekend.
Richarlison's fate has come into focus after Tottenham's aggressive summer of spending to boost their fortunes after avoiding the drop by coming 17th in the Premier League last season.
Tottenham have yet to recruit a striker, but De Zerbi has made clear he is not finished in the transfer market yet with Manchester City forward Savinho among those reportedly in his sights.
"I don't know," De Zerbi said when asked about Richarlison's future after the Chelsea match.
"As a player, as a guy, it is unbelievable his attitude and behaviour, but at the end we have to respect what he wants to do.
"For me he is still an important player because it is not so easy to find another striker as Richarlison, because Richarlison scores goals and he knows the way."
Pressed on whether he would leave, De Zerbi said: "I don't know, I didn't understand well, because sometimes he said to stay, sometimes he leaves.
"We have to speak anyway, there is not any problem. He is a lovely guy.
"All of us love him, the teammates, the club, the staff, because he works hard every day, seriously every day, and we can't say anything else."
Richarlison, who is entering the final year of his contract, scored 12 goals last season.
Get ready for the new Premier League season
The Premier League returns on Friday, August 21st as defending champions Arsenal host new boys Coventry in the 2026/27 curtain-raiser.
Get ready for kick-off ahead of the new season:
- Transfer Tracker: All the latest done deals and rumours
- Premier League fixture list revealed for 2026/27
- All Premier League and top European club kits for the 2026/27 season
