|Ashes 2015: England v Australia|
|Venue: Edgbaston, Birmingham Date: 29 July - 2 August|
|Coverage: Live Test Match Special radio and text commentary on every match on BBC Radio 5 live sports extra & BBC Sport website, plus desktop, tablets, mobiles and app.|
"It could be the end" for Ian Bell's Test career if he does not score runs in the third Ashes Test, says former England opener Geoffrey Boycott.
Bell, 33, has been moved up to bat at three after Jonny Bairstow was brought into the side to replace Gary Ballance.
"They can't go on with someone not getting runs," Boycott told BBC Radio 5 live.
Meanwhile, Bairstow said he "wasn't even thinking about" a return to the England team.
The Yorkshire batsman, 25, has played 14 Tests, the last of which came against Australia in the Ashes series down under in January 2014.
"I haven't been concentrating on anything apart from scoring runs for my county," he told BBC Look North.
"The chance has come and I am delighted. It has been a case of working hard over the last few years and just going out and playing. A few things have come together.
"Consistency-wise I think I am in my best form and striking the ball well and hopefully this will continue."
Bairstow will bat at five in the Edgbaston Test, with Bell moving up to replace Ballance at three and Joe Root - another Yorkshireman - going from five to four.
"I am desperately disappointed for Gary," added Bairstow. "He has scored a heck of a lot of runs for England over a short period of time."
'Bell has to take responsibility'
Warwickshire's Bell is one of the senior players in the team and has played 112 times for the side. The right-hander has scored 22 centuries at an average of 43.18.
However, he has endured a difficult summer, making just 116 runs in eight innings and Boycott feels Bell needs to step up and act as a leader.
"If you have played over 100 Tests, you need to take responsibility for the very difficult position of number three," said the Yorkshireman.
"You need to be a bit like an opener. The way England are playing at the moment, they definitely need three openers at the top. Bell has to shoulder that responsibility and go up front. He needs to help the other guys out.
"The selectors are saying, 'if you don't perform at three, you are gone'. I love Ian Bell and his cricket, he is beautiful to watch, but if you don't have the mind or the defensive technique against pace bowling, you are going to get out."
'Jonny has earned the opportunity'
Bairstow has made 593 runs for England at an average of 26.95 since his debut against West Indies in 2011.
This season he has scored five centuries in the County Championship, including 139 in Yorkshire's current match against Worcestershire.
But he has not played for his country since the last Test of the 5-0 thrashing by Australia in the last Ashes series down under.
|England's top order at home this summer|
Yorkshire coach Jason Gillespie - who was in the running for the England job before the appointment of Trevor Bayliss - says Bairstow's hard work has paid off.
"It came down to Jonny as an individual, he has done this," said Australian Gillespie. "I am delighted for him. He has earned the opportunity because of sheer weight of runs.
"He stripped back his game. He was trying a lot of different things which were not quite working. He went back to playing as natural as possible and focusing on scoring runs as opposed to worrying about his technique."
Yorkshire director of cricket Martyn Moxon told BBC Radio 5 live: "His temperament is good, he is in brilliant form this season so will be full of confidence.
"He will go and play his natural game, which is to try to attack whenever possible. He is in great form so I am pleased for him to get the opportunity again."
BBC Sport's cricket correspondent Jonathan Agnew added: "Ballance looks so out of form. You can see batsman battling, struggling and being up against it. It is a bit like that for Ian Bell at the moment.
"Ballance looked all at sea - it happens to batsmen, they do lose form. He will have to go away, get some form and come back.
"Bairstow is a free-scoring player but he is chirpy, he has a bit about him. He is a joker, a bit of a character to lift the dressing room after the awful defeat at Lord's."