According to Goal.com, Tottenham are interested in signing 24-year-old Cameroon international goalkeeper from Ajax in the summer transfer window.
Meanwhile, The Express has reported of interest in 23-year-old Netherlands international midfielder Van de Beek from Newcastle.
Both Spurs and Newcastle have been boosted in their reported quest to sign Onana and Van de Beek respectively, with Van Der Sar saying that there is already an agreement with the two players that they will be sold this summer.
Van der Sar told Sky Sports: “Last year, we made verbal agreements with [Andre] Onana, [Nicolas] Tagliafico and Van de Beek to stay another season, and then we look to help each other and find the next step in their careers.
“Nothing has changed. There won’t be a 50 per cent discount. The clubs can forget about that.”
Onana made 24 appearances in the Eredivisie, played six times in the Champions League and once in the Europa League for Ajax this season, according to WhoScored.
Van de Beek made 22 starts and one substitute appearance in the league for Ajax this campaign, scoring eight goals and providing five assists in the process, according to WhoScored.
The Dutchman scored two goals and provided one assist in five Champions League matches, and provided one assist in two Europa League games, according to WhoScored.
Football in England is suspended at the moment, while the Eredivisie has already been called off due to the global health crisis, and it is not clear when the summer transfer window will open.