Ireland has called up Connacht hooker Dave Heffernan and Ulster scrumhalf Nathan Doak to replace injured players Dan Sheehan and Craig Casey for the second Test against South Africa in Durban. Sheehan suffered a knee injury, while Casey suffered a severe concussion during the first Test. Heffernan and Doak, who arrived in Durban, will join the squad as replacements. The IRFU has confirmed that Sheehan and Casey will not participate further in the series. Additional medical updates on other injured players are expected later in the week.