Aim: This paper reviews breaches in managed biosecure environments (BSEs) in cricket since the onset of the Omicron variant. Background: Managed BSEs have allowed return to international cricket since the onset of the COVID-19 pandemic. The Omicron variant however disrupted three tours since its onset, with rapid spread through teams. The West Indies (WI) tour of Pakistan and Ireland tour of USA in December 2021, and Ireland tour of WI in January 2022 were all affected by an Omicron outbreak. The design of the BSE was examined. The mean time from symptoms to positive test, and the number of negative tests prior to becoming positive were calculated. The symptoms were recorded. Case series: Twenty-four of 28 members of the WI squad ultimately tested positive; nine while in Pakistan and 13 on returning early to the Caribbean. The mean time between having symptoms and returning a positive polymerase chain reaction (PCR) test was 2.71 days (range 1–9 days). Each player had 0–4 negative PCR tests (mean 2.34) prior to returning a positive test. Nine of the positive persons were asymptomatic, while those with symptoms resolved within 48 hours. Eleven of 38 Irish squad members tested positive, but positive family members forced others into isolation. Symptoms were all mild and mostly sore throats. Whereas the disease was mild, its virulent nature infected enough of the squads to affect fixtures. On-field exposure did not cause cross-team infection. Conclusion: The Omicron variant is virulent though mild. However, once it enters a squad it spreads quickly but may take time to show positive on PCR or rapid antigen test (RAT). Whereas BSE protocols during this outbreak may need to be tightened as once contracted it leads to disruption of series, an alternative approach may be to treat symptomatic individuals as one does the common flu and isolate them alone. Clinical significance: With increased vaccination rates among cricketers and decreased symptoms with newer COVID-19 variants, and little spread across teams in open spaces, the approach of BSE may need to be changed to treat outbreaks symptomatically.