Nathan Lyon’s chances of playing any further part in the Ashes look slim after Cricket Australia confirmed he had suffered a “significant” calf strain.

Lyon had arrived on the third morning at Lord’s on crutches after he had to be helped off the pitch on Thursday evening after pulling up with a calf problem during his fielding stint in the deep.

The Australia spinner, playing his 100th consecutive Test, looked distraught as he hobbled around the boundary edge and, when he joined his team-mates at the ground on Friday morning, his reliance on crutches raised alarm bells over his chances of being fit for the last three Tests of the series.

A Cricket Australia spokesperson said: “Nathan Lyon has been diagnosed with a significant calf strain. He will require a period of rehabilitation after this match is concluded.

“A decision regarding his availability for the remainder of the series will be made at the conclusion of the game.”

Lyon had a scan on Thursday night before a further assessment took place ahead of day three getting under way, but no grading has been attached to his calf strain.