Jos Buttler believes Jofra Archer's "X factor" can re-energise England's Ashes challenge.

Paceman Archer is in line to make a much-anticipated Test debut at Lord's this week as a replacement for England's record wicket-taker James Anderson, who is sidelined by a calf injury.

Australia took a 1-0 lead in the five-match series after winning the first Test at Edgbaston by the thumping margin of 251 runs.

"He's got the X factor," Buttler said of fellow World Cup winner Archer at a Kookaburra sponsorship event at Lord's.

"In his short international career so far we've seen what an impact he's had.

"He's got amazing skills with the white ball, but talking to him he prefers bowling with the red one.

"That's exciting for us, and it's exciting for the world to see him in the Test arena.

"He tends to cope with expectation well, he's a pretty laid-back character who has an immense trust in his game. So if he gets his chance I expect him to perform really well."

Australia ran out convincing first Test winners despite stumbling to 122 for eight on the opening day.

England claimed a 90-run lead on first innings before being bowled out for just 146 on the final day.

"We played some good cricket at Edgbaston, but we didn't play well enough for long enough," Buttler said.

"The challenge is still the same. Every time you come and play at Lord's is special, especially in an Ashes Test.

"There's no need to panic, we're 1-0 down, but there's four matches to go in this series.

"We know we've got a fantastic team and we've got to stay calm. Nothing really changes.

"We've lost that game, but we've got enough belief to make it one-all."

The key to England's hopes is finding a way to dismiss Steve Smith, who scored two hundreds in the Ashes opener and now averages nearly 63 in Test cricket.

Smith scored 144 and 142 at Edgbaston upon his return to Test cricket after the ball-tampering scandal in March 2018.

Buttler knows Smith well as the two men were team-mates at the Rajasthan Royals in the Indian Premier League this year.

"He's pretty good, isn't he?" Buttler said. "What he does is put you under pressure for a long period of time and puts demands on you.

"He's a fantastic player who can take advantage of that.

"He's been one of the best players for a while now and that's the challenge of playing Test cricket against Australia."