Speaking of Howlett's injury which he picked up against the Ospreys last Saturday, Paul O'Connell said: "It's hugely disappointing to lose a player like Doug.
"He's been a role model for everyone, young lads, fellas like me, the way he turns up at training every day. The professional way he's always conducted himself.
"He lways gives it his all and then goes out and produces it again on the field. There was a despondency in our dressing room on Saturday when we knew it (injury) wasn't good.
"But knowing the sort of guy he is, I wouldn't be writing him off. He'll be back."
In other Munster injury news, Keith Earls (knee) is expected to return to training next week with the possibility of playing in the home Heineken Cup match against the Scarlets. Earls was in UL this afternoon but took no part in the session.
Other players due to return from injury include Peter Borlase (back), who may take part in the British & Irish Cup game in Tralee on Saturday, and David O'Callaghan (knee) who could also line out for the province's 'A' side.
Darragh Hurley, however, continues to be dogged by injury. He has recovered from an Achilles problem only to then sustain a back (disc) injury that could see him sidelined for up to three months.
Ivan Dineen looks set for a return next week, while David Wallace and Felix Jones both continue to impress with their rehab progress - there are February/March and January/February time frames for their respective returns.
Finally, news on Jerry Flannery is less definite other than it will be the New Year before he might be back playing.