Saracens have named Mako Vunipola in their team to face Bath on Sunday despite being obliged to rest him according to an agreement between the Rugby Football Union and the Premiership.

In a move that raises serious concerns over player welfare, Vunipola has been picked for the fourth week in a row following the Six Nations, even though the terms of the Professional Game Agreement (PGA), signed in 2016 between the RFU and the Premiership, suggest he must be given a break. According to the Premiership Rugby website, the PGA states that: “Those [players] who play throughout the Six Nations, and pass a threshold of minutes played, will have one weekend off in the four weeks following the competition.”

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The Guardian has been told by the RFU that in order to get the mandatory rest period, a player will have had to play in all five Six Nations matches and for at least 80% of the total aggregated minutes. That applies to the loosehead Vunipola on both counts.

He went on holiday to Tenerife after the Six Nations but was a used replacement in Saracens’ win over Harlequins a week after England’s tournament finale against Ireland. He started the Champions Cup quarter-final defeat by Leinster eight days later, and the victory over Northampton last weekend. Yet he has been chosen against Bath, even though Saracens have rested Maro Itoje, another player who met the requirements for a rest.

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It is understood the RFU does not have an issue with Vunipola playing against Bath as he was allowed his holiday and because Saracens do not have a game next week, having lost in the Champions Cup. It is also understood Saracens are aware Vunipola meets the requirements for a mandatory rest and have been contacted for a comment.

It is particularly concerning, however, at a time when there is concern over player welfare and when discussions over restructuring of the domestic season are at such a crucial juncture before next week’s Professional Game Board meeting looming.In addition, it raises questions over the workload England players are subjected to after their worst ever Six Nations finish. Fatigue has been raised as a key factor behind England’s recent failures with players from Ireland, in particular, as well as Wales and Scotland afforded far more rest during the season.

Meanwhile, Newcastle kept their Premiership play-off dreams alive on Friday with a dramatic 35-30 victory over Sale, whose own hopes of a top-four finish took a hit.

Newcastle had looked to be cruising to victory after building a 25-0 lead and securing a try bonus point inside the first half hour. But Sale roared back in style with 27 unanswered points and it needed a Rob Vickers try in the dying minutes to earn Newcastle victory at Kingston Park.

The win moves Newcastle up to third ahead of the weekend’s fixtures. Sale remain sixth.