Gatland said Howley, the former Wales scrum-half and captain, was "devastated" by the bombshell turn of events that has thrown the Six Nations champions' preparations into disarray.
Sri Lanka Cricket Secretary Mohan de Silva said he was satisfied with the security arrangements of their hosts, but reports last week of a possible terror attack had been referred to the defence ministry for investigation.
The Citizens have dropped two points against SuperSport United last weekend after 3-3 draw that saw Thabo Nodada bragging a brace and man of the match award.
Quinton de Kock has been handed the formal leadership in the absence of regular captain Faf du Plessis, who will return for next month’s Test series against India.
The team hit the ground running at training at the Madibaz Stadium this week following the friendly between SA Select Women and Spain Invitational XV last Saturday, which the visitors won 17-5.