James Anderson and Stuart Broad remain almost certain picks in Test cricket if they are fit, says new England coach Chris Silverwood.
Anderson, 37, missed virtually all of the Test summer with a calf injury and is training at Premier League champions Manchester City in a bid to boost his chances of being ready for this winter's tour of South Africa.
Broad, 33, led the attack superbly in Anderson's absence, taking 30 wickets in six matches as England beat Ireland in a one-off Test and then earned a 2-2 draw in the Ashes.
"If they're both fit, it's difficult to look past them, isn't it?" said Silverwood, who has worked closely with the pair during his previous role as England's bowling coach.
"Jimmy's great. He gets wickets all around the world, he's got a lot of knowledge in there that he can share with the players coming in.
"I think it will be up to him to let us know, and I think he will, when he's had enough, but who wouldn't want a world-class bowler like him in the line-up? He is phenomenal."
Jofra Archer impressed in Anderson's stead during the Ashes, taking 22 wickets in four Tests and, at times, reaching speeds of 95 miles an hour.
Sam Curran and Saqib Mahmood could play a big part in England's future, too, and Silverwood knows he must prepare for the post-Anderson and Broad era.
"I want [Anderson] around as long as I can, but equally we've got to be realistic and say 'right we've got to do some future planning here'," said the former Essex coach.
"We've got to sit down and make sure we've got depth so when guys do retire we've got people coming through who can take their places.
"It's a great headache to have. When you look at the amount of wickets [Anderson and Broad] have got between them, it's phenomenal."
The new head coach echoed similar views regarding World Cup-winning captain Eoin Morgan, who has committed to carrying on as skipper until at least the T20 World Cup in Australia next year.
"The way he leads that one-day side and T20 side, and the influence he's got with the players, is phenomenal," Silverwood added of the 33-year-old.
"He's so respected, the ideas he has. My job is to give him as much support as I can to help him get where he wants to get to with them.
"There's got to be an eye on when it's not Eoin any more, who is it going to be? Eoin's got to be very much involved in that conversation as well.
"He's earned the right to tell us when he's had enough but certainly we've got to have one eye on transitioning that period."
Watch England's tour of New Zealand live on Sky Sports Cricket next month.