Williams has started every Test he has been available for since Tandy took the reins in the summer of 2025.
The only fixtures he has missed – last November’s defeat by South Africa and June’s win in the uncapped game against the Barbarians – were outside World Rugby’s international window.
The former Cardiff scrum-half, who swapped Gloucester for Saracens in the summer, has played past the hour in every outing under Tandy.
Wales won three Tests in 2025-26 and Williams played the full 80 minutes against Japan and Fiji, while he came off with just two minutes left against Italy.
The 31-year-old played 378 minutes in the 2026 Six Nations, with 10 of those minutes on the sidelines due to a yellow card against Ireland.
In comparison, France’s Dupont played 357 (Lucu was injured), Ireland’s Jamison Gibson-Park 323 and Scotland’s Ben White 302.
Williams has shared matchday squads with just two scrum-halves under Tandy – Ospreys’ Kieran Hardy and Reuben Morgan-Williams.
Hardy, who started against South Africa and the Baa-Baas, made five brief appearances off the bench while Morgan-Williams came on three times.
But there is likely to be a new inclusion when Tandy names his group for the Nations Championship.
Hardy faces a lengthy lay-off after suffering a knee injury against Dragons earlier this month.
His misfortune could lead to more opportunities for Morgan-Williams, who has had to show patience at international level.
Ospreys head coach Mark Jones said of him last season: “He’s a real competitor and has got a real appetite on both sides of the ball. He injects speed into the game.
“What I like about him is his personality. He’s just straight-talking, no messing around.”
Tandy must find a third specialist as he counts down to the World Cup, where he will have another decision to make.
Warren Gatland initially went with two scrum-halves in 2023 – Williams and Gareth Davies – before adding Hardy for injured number eight Taulupe Faletau before the quarter-final defeat by Argentina.
