Bristol, Jul 27 (IANS): England middle-order batter Jonny Bairstow is a doubtful starter for the opening T20 International against South Africa here later on Wednesday after the 32-year-old was seen doing an unusual training drill that saw him carrying team-mate Sam Curran on his shoulders, according to a report in Daily Mail.

The report said Bairstow was filmed carrying Curran on his shoulders "while doing lunges", adding the all-format player had potentially sustained a right knee injury.

Bairstow was reportedly seen leaving training in discomfort with ice packs and his left knee heavily strapped.

However, the England and Wales Cricket Board (ECB) has not given an update on whether he will be in the playing XI for the T20I game or not against the Proteas.

With back-to-back T20Is lined up, it would be no surprise to see Bairstow being left out of the playing XI on Wednesday, the report said.

Bairstow had said recently he wants to play all three formats of the game for "as long as possible", despite his team-mate, all-rounder Ben Stokes retiring from ODI cricket at the age of 31 and Australia batter Usman Khawaja admitting that it is tough playing all formats in international cricket.

On Wednesday an Instagram video shared by pace-bowling teammate Reece Topley gave a likely clue of what might have caused the injury to Bairstow. In the video shared by Topley, Curran can be seen draped over Bairstow's back as the charismatic batter completes a "walking lunge in the gym".

Bairstow has smashed four hundreds in his previous five innings, which have contributed to England's turnaround in red-ball cricket.