Mackenzie was due to make his first appearance in the WSBK on April 23-24 with the same McAMS Yamaha team that guided him to last year's BSB title, riding a slightly different iteration of the R1 bike he is accustomed to.
However, just weeks before his planned debut, the 26-year-old suffered a major crash during an official BSB pre-season test in the wet at Silverstone, requiring an immediate trip to the trackside medical centre.
Mackenzie was diagnosed with a broken left ankle and subsequently had to undergo surgery on the injury on April 11.
While the treatment was a success, the British rider has to spend a certain number of weeks at home to complete a full recovery, ruling him out of both this weekend's BSB season opener at Silverstone as well as the following week's WSBK round at Assen.
Mackenzie and his team McAMS are now planning to race in the WSBK later in the year, although further details are unavailable at the moment.
Initially, Mackenzie was aiming to make a full step-up to the WSBK in 2022 on the back of his title-winning campaign in his home country - a route several of his compatriots had taken in the past.
However, his hopes of joining the world championship were dashed when GoEleven elected not to leave the Ducati fold in favour of Yamaha, leaving him with no option but to remain in BSB and defend his crown.
