Lumb underwent surgery after suffering a torn tendon in his arm while playing in the Big Bash in Australia.
He will be out for at least three months, ruling him out of the first month of the new season.
Nottinghamshire physio Jon Alty told the club???s website: ???Michael???s surgery was successful, and he???s due to begin rehab shortly, but I don???t want to put a date on his full recovery.
???He???ll be doing gentle rehabilitation work for the next four to six weeks, before a full return to batting programme from eight weeks.?????
Nottinghamshire will look to Greg Smith, signed from Leicestershire at the end of last season, and the versatile all-rounder Steven Mullaney, to fill the void.
Director of cricket Mike Newell said: ???The surgery was necessary if we???re going to see him back fully fit. This is a huge opportunity for players to impress, take advantage of the space in the team and step up.
???Greg Smith and Steven Mullaney will see this as a chance to get into our team and get our season started in the right manner.?????
Young batsman Jake Libby, who scored a century on his debut against Sussex in September, will not be available until later in the season after undergoing surgery on torn cruciate ligaments.
He suffered the injury while playing for Latrobe in Tasmania.
?????Jake???s is the best ACL reconstruction I???ve ever seen,??? added Alty. ???We???re still in the very early stages, but are on track for the planned six-month return to action.
???He???s back in the gym, and is due to start running soon. Having a player as dedicated to recovery as Jake is excellent to see.”