Lions head coach Swys de Bruin skipped the South African team's impressive Super Rugby victory over the Chiefs in Hamilton, to return home due to a "serious medical condition".
South African newspaper Rapport reported de Bruin told his wife, Marilize, and the Lions management on Wednesday that his health had deteriorated after which he was instructed to return to Johannesburg immediately.
De Bruin was notably absent from the Lions team that beat the Chiefs 23-17 on Friday night, after racing out to a 20-0 halftime lead.
Assistant coach Ivan van Rooyen was in charge of the team and will again lead the side when they take on the Crusaders in Christchurch on Friday.
Although de Bruin refused to comment on the nature of his condition, Rapport claimed the 59-year-old has been suffering from a "nervous condition" brought on by the team's recent struggles on the pitch.
The Lions suffered back-to-back defeats (including a 42-5 humbling at the hands of the Sharks) before surprising the Chiefs and since the Lions' shock loss to the Sharks last weekend.
De Bruin denied earlier suggestions that he'd had a disagreement with senior players ahead of the Chiefs match
"I guarantee you 100 per cent that there is no issue between me and anyone in the team. There was no interference (in team selection) ... It's a personal medical issue and I'm receiving professional help.
"The team know this and I have their full support."
De Bruin took over as Lions coach from the highly successful Johan Ackermann in July 2017 after Ackermann left for Gloucester in England.
The Johannesburg-based outfit lost to the Crusaders in last year's final but have had mixed results this year - losing four of their nine matches this year.