ANTHONY Watson and Mako Vunipola will be released by England to play for Bath and Saracens this weekend as they bid for starting places in the RBS 6 Nations clash with Scotland.

The pair have been named in Eddie Jones' 27-man squad for this week's training camp in Oxford, the Rugby Football Union announced, as preparations continue for the Calcutta Cup contest at Twickenham on March 11.

Exeter centre Henry Slade, who came off the bench in the 36-15 win over Italy at Twickenham, has been omitted, but Bath centre Jonathan Joseph is back after being dropped last week.

Bath teammate Watson returned to England's training squad for last Sunday's win over Italy, but did not make the matchday 23 and will be given a further opportunity to boost his fitness in Bath's Aviva Premiership clash with Wasps on Saturday.

Vunipola, who came off the bench against the Azzurri, will be made available to Saracens for their clash at Newcastle as he seeks to displace Joe Marler at loosehead prop against the Scots.

Meanwhile Bath have signed Bristol hooker Chris Brooker on loan, while Shaun Knight and Michael Van Vuuren have completed contract extensions at The Recreation Ground.

Brooker returns to Bath for his second spell at the club in a deal to run until the end of the season to ease a spate of front-row injuries.

Former Gloucester prop Knight joined Bath in September from the Dragons and has now extended his contract until the summer of 2018.

South African hooker Van Vuuren joined Bath from Leicester last summer and has now penned a two-year contract extension.

"We're really pleased to have been able to bring someone who has as much experience as Chris in at this stage in the season," said Bath rugby director Todd Blackadder.

"We've lost Tom Dunn and Jack Walker in recent weeks to injury, so to have Chris in the squad will be a huge boost heading into a critical part in our season.

"It's been a busy month or so with contract renewals, but we're delighted to have secured a number of players in preparation for next season.

"Shaun and Michael are another two players that we had identified as playing an important role at the club and I have no doubt they will offer a great deal to the squad during their time here."

Former England Under-20s prop Knight admitted he had little hesitation in prolonging his spell at The Rec.

"I'm really happy to have extended my stay at the club," said Knight.

"It's been an extremely enjoyable six months and to be a part of a squad that has the potential of challenging for honours is really exciting."

Van Vuuren has enjoyed spells with Stade Francais as well as the Cheetahs in Super Rugby and represented South Africa's Under-20s.

"I've really enjoyed my time here so far, so when the opportunity came to stay at the club I did not hesitate," said Van Vuuren.

"The environment and culture that is being created at the club is a special one and I'm looking forward to being a part of the journey."