| Sai van Wermeskerken | |
| Birth Date: | 28 June 1994 |
| Birth Place: | Maastricht, Netherlands |
| Position: | Right-back |
| Currentclub: | Kawasaki Frontale |
| Clubnumber: | 31 |
| Youthyears1: | 2002–2008 |
| Youthclubs1: | Yatsugatake Hokuto |
| Youthyears2: | 2008–2013 |
| Youthclubs2: | Ventforet Kofu |
| Youthyears3: | 2013–2015 |
| Youthclubs3: | Dordrecht |
| Years1: | 2015–2017 |
| Clubs1: | Dordrecht |
| Caps1: | 64 |
| Goals1: | 1 |
| Years2: | 2017–2019 |
| Clubs2: | Cambuur |
| Caps2: | 66 |
| Goals2: | 1 |
| Years3: | 2019–2022 |
| Clubs3: | PEC Zwolle |
| Caps3: | 47 |
| Goals3: | 0 |
| Years4: | 2022–2023 |
| Clubs4: | Cambuur |
| Caps4: | 24 |
| Goals4: | 1 |
| Years5: | 2023–2024 |
| Clubs5: | NEC Nijmegen |
| Caps5: | 3 |
| Goals5: | 0 |
| Years6: | 2024– |
| Clubs6: | Kawasaki Frontale |
| Caps6: | 5 |
| Goals6: | 0 |
| Nationalyears1: | 2016 |
| Nationalteam1: | Japan U23 |
| Nationalcaps1: | 5 |
| Nationalgoals1: | 0 |
| Club-Update: | 20 January 2024 |
is a professional footballer who plays as a right-back for Kawasaki Frontale. Born in the Netherlands, he is a former youth international for Japan.
Van Wermeskerken was born in Maastricht, Netherlands, to a Dutch father and a Japanese mother. When Sai was only 2-years old, his family moved to Japan after his father had got a job there. The van Wermeskerken family settled down in Yamanashi Prefecture. Van Wermeskerken started his career at Yatsugatake Hokuto at age eight, before joining Ventforet Kofu youth academy in 2008.
After several years in the Kofu youth system, van Wermeskerken was rewarded with a contract by Dordrecht in July 2013. He made his first appearance for Dordrecht on 10 May 2015, in the Eredivisie match against Twente.[1]
On 21 August 2017, van Wermeskerken signed for SC Cambuur.[2]
On 9 July 2019, van Wermeskerken signed a two-year deal for Eredivisie side PEC Zwolle on a free transfer.[3]
On 10 August 2022, van Wermeskerken returned to Cambuur for one season.[4]
On 27 October 2023, van Wermeskerken joined Eredivisie side NEC Nijmegen, signing a contract until the end of the 2023–24 season.[5]
On 21 January 2024, NEC announced van Wermeskerken's transfer to Japanese club Kawasaki Frontale.[6]
On 14 March 2016, Sai received his first call-up to the Japan national under-23 football team for the friendly match against Mexico.[7]
Kawasaki Frontale