South Africa fast bowler Kagiso Rabada has been ruled out of two Twenty20 Internationals against Ireland this week and is also a doubt for the three-match Test series against England as he works his way back from a medial ligament injury in his ankle.

Rabada is a key strike bowler for South Africa in the longer format and his absence would be a huge blow to the tourists’ hopes of success in the England series, which starts at Lord’s on Aug. 17.

Cricket South Africa said on Tuesday the 27-year-old would be closely monitored ahead of the Test series but offered no time frame on a potential return to action.

He is definitely out of the T20 games against Ireland that will be played in Bristol on Wednesday and Friday.

South Africa will look to cement their lead in the World Test Championship with a series win against a resurgent England, who have been fearsome with the bat under new coach Brendon McCullum, beating India and New Zealand in their last four tests.