Steve Waugh says Australia must stand by opener Cameron Bancroft "for the long term" despite his tough start to the Ashes.

Bancroft's first three knocks of the series in England have returned eight, seven and 13, while he was the victim of Jofra Archer's maiden Test wicket at Lord's on Friday.

Fellow opener David Warner has also struggled so far, contributing two, eight and three, even though Australia thrashed England in the first match at Edgbaston.

Bancroft, Warner and star man Steve Smith - who made two centuries in Birmingham - are all playing Test cricket for the first time since bans for their role in the team's ball-tampering scandal in South Africa last year.

It is Bancroft, 26, whose position is being questioned at this stage, but Waugh, the team's mentor, is preaching faith in the Durham captain.

"I thought Bancroft hung in there pretty well," Waugh said after Australia ended a rain-affected third day on 80-4 in their first innings, 178 runs behind.

"He just needed to spend another half-hour there, get a few more balls away out of the middle and he would have been right.

"It's a fine line. You can analyse and scrutinise players but that's Test match cricket. Sometimes you are going to miss out. If you pick a guy, you back him for the long term and, right now, we are confident those guys are going to bounce back.

"[Bancroft and Warner] both want to get a lot more runs obviously, but Test match cricket is tough. It's challenging and the conditions over here are not easy for batting.

"It's not as if the ball is coming on and you can play a big cover drive. You have to work really hard for every run.

"And both bowling attacks are world class. You are up against some really quality bowlers who have taken a lot of wickets, have a lot of experience and a lot of know-how, and you've got to work hard for your runs."

In a further defence of Bancroft, Waugh added: "Cameron's preparation for this Test was excellent. He looked really good in the nets and he's pretty relaxed at the moment.

"He'd like some more runs but I am backing him to do well. He's a thoroughly professional cricketer, a nice, decent guy who works hard at his game.

"He's dedicated and he's disappointed he missed out, but he's the sort of cricketer who's tough and he'll come back."