Nathan Lyon's prospects of playing any further part in the Ashes looked to be fading fast as he arrived at Lord's on Friday on crutches.

The Australia off-spinner limped off during Thursday's second day of the second Test at the 'Home of Cricket' after pulling up with a calf problem having run in from the boundary while fielding.

The 35-year-old, appearing to wipe away tears, eventually limped around the boundary edge towards the dressing room while a staff member held on to stop Lyon losing his balance.

Lyon, appearing in his 100th consecutive Test, joined his team-mates at Lord's on Friday morning.

But the fact he was using crutches and wearing a compression sock suggested he would not be regaining full fitness anytime soon.

It now seems highly unlikely that Lyon will play any further part at Lord's, while a three day turnaround before the third Test at Headingley means it would be remarkable if he played in Leeds.

Cricket Australia have yet to provide a fresh update on Lyon's fitness but team-mate Steve Smith was concerned when asked about the bowler's injury after Thursday's close.

"Obviously it didn't look good," he said. "I mean it doesn't look ideal for the rest of the game. I'm not sure how he actually is, but if he is no good, it is obviously a big loss for us.

"Fingers crossed he is okay but it didn't look good."

Australia have a trio of part-time spinners -- Smith, Travis Head and Marnus Labuschagne -- who may now have to cover Lyon's absence at Lord's.

And should Lyon be ruled out of the third Test, reserve spinner Todd Murphy could be called up at Headingley.

Ashes-holders Australia, bidding for a first Test series win away to England in 21 years, are 1-0 up in the five-match campaign after a two-wicket win at Edgbaston.