The scan has shown that Howlett ruptured his Achilles and he'll undergo surgery later this week In Dublin.
Other injury news is that Keith Earls, Peter Borlase and Dave O'Callaghan are all due to return to action, Earls expected to return to full training next week while Borlase (back) and O'Callaghan (knee) could be involved in the British & Irish Cup game against Ayr in Tralee on Saturday.
Prop John Ryan (groin) is looking at a return to training in three weeks, Mike Sherry (ankle) in six weeks and Ivan Dineen likely to be back next week.
Felix Jones and David Wallace continue their rehab with expected return around February while Jerry Flannery is also looking towards a New Year return.
But Darragh Hurley continues to be dogged by injury. Having recovered from an Achilles he has since been troubled by a disc in his back that could see him sidelined for a further 3 months.
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