Former Australia captain Ricky Ponting believes the ankle injury affecting Mitchell Starc is a big concern ahead of next week’s second Ashes Test at Lord’s.

The left-arm quick has been battling pain in his right ankle since bowling on day one in Cardiff and showed great courage to get through 16 overs in England’s second innings on Friday to finish with 2-60.

With only three days between the scheduled close of play on Sunday and the start of the Lord’s encounter, Starc could face a race against time, with Peter Siddle in line to take his place should he not be fit.

Michael Clarke’s side face an uphill task to avoid defeat in the opening Test, needing 412 batting last on a pitch that is showing some signs of deterioration at Swalec Stadium.

With Ryan Harris forced to retire last week due to a knee injury, the tourists bowling stocks are already stretched and the loss of Starc, who finished with match figures of 7-164, would be a hammer blow, especially if they are defeated in the Welsh capital.

The left-armer bowled two maidens at the start of England’s second innings, but was late to take the field. He looked restricted at times in the field and grimaced as he followed through to the popping crease.

“This is a real concern for the Australians,” Ponting said on Sky Sports.

“There’s obviously something going on there with the ankle.

“It’s unusual for him not to be out there, so there’s some sort of medical situation going on.”

The full extent of Starc’s issue is yet to be revealed by Cricket Australia, but the NSW speed merchant does have a history of bone spurs and underwent surgery ahead of the 2013 series.

England batsman Ian Bell, who was dismissed by Starc in the first innings, said he realised the 25-year-old was in pain but said he hadn’t noticed any loss of pace when facing him.

“He looked in some discomfort … but you’d expect someone – well any of the Aussie bowlers are going to keep running in.

“That’s what he did and even if he was going through pain, he didn’t really show it on the field. That’s what you expect from those guys.”

Teammate Nathan Lyon hailed the contribution of Starc, who still managed to bowl in excess of 140kph.

“Starcy’s performance carrying an injury is fantastic,” Lyon said.

“To have the courage to come out there and still bowl consistently in the 140s … the credit goes to Mitch.

“The bowlers dug deep today to give him a couple of extra days rest before the second Test.”