The England prop Kieran Brookes will miss the start of the Six Nations after knee surgery, the third player to be lost to the national head coach, Eddie Jones, in his first month in charge.

Brookes’s fellow Northampton prop Alex Corbisiero is taking the rest of the season off following another knee operation and the Exeter centre Henry Slade is unlikely to play again until March after breaking a leg at Wasps. Jones names his first squad on 15 January.

Brookes’s post-World Cup form for Northampton established him as a strong contender for the England tight-head jersey in the opening Six Nations match against Scotland at Murrayfield in February. He was injured against Racing Métro in the European Champions Cup.

“He will be out for quite a few weeks,” said the Northampton director of rugby, Jim Mallinder. “It is a big blow because he was playing and scrummaging really well.”

Northampton struggled up front without Brookes against London Irish in the Premiership on Saturday at the Madejski Stadium and the Exiles secured their first league win of the season two minutes from time when they were awarded a penalty try after Northampton collapsed a scrum near their line.

“It may have been a bit early to make that call but I am not going to make excuses,” said Mallinder after his side went down to a fourth defeat in seven Premiership matches. We need to look at various parts of our game and start stepping things up. We have to start the new year better than we finished this one.”

His London Irish counterpart, Tom Coventry, said he was relieved at his side’s first league points of the campaign, which took them off the bottom of the table. “I was very pleased with the fibre shown by the players. Perhaps motivation has been lacking but not today. We have to take confidence from this.”