Worcester boss Alan Solomons admitted he has "massive concern" about the neck injury suffered by former Hurricanes lock Michael Fatialofa during the side's 62-5 Gallagher Premiership defeat at Saracens.
Fatialofa had been on the pitch for just over a minute when he was hurt while takingthe ball into contact.
Play was held up for almost 10 minutes as he received medical attention and, having been carried from the pitch on a stretcher, he was taken by ambulance to St Mary's hospital accompanied by the team doctor and a travelling reserve.
Fatialofa, 27, made his New Zealand domestic rugby debut for Southland in 2011, before shifting to his home town of Auckland for the 2015 ITM Cup.
That move proved profitable for Fatialofa as, after one season with the province, he was selected to play for the Hurricanes in Super Rugby where he helped the side to their maiden title.
Fatialofa is currently signed with Worcester on a two-year contract from the 2018-19 season.