The 28-year-old's career was seemingly in the balance when Red Devils boss Sir Alex Ferguson revealed last month that the Scotland captain was yet to return to training following a long-standing chronic bowel complaint.
But Levein, who named his squad for the upcoming friendly with Australia this morning, confirmed Fletcher is now on his way back to playing competitive football for the first time since November.
Striker Jordan Rhodes got his second senior call-up, following his full debut as a late substitute against Cyprus in November.
Southampton defender Daniel Fox is in line for his first Scotland cap in almost three years. The 26-year-old picked up his only cap to date in a 3-0 defeat to Wales during his brief stint at Celtic but looks set to add to that as Rangers left-back Lee Wallace misses out. There was also a recall for Cardiff City goalkeeper David Marshall.
Don Cowie (Cardiff City)
James Forrest (Celtic)
Daniel Fox (Southampton)
Matt Gilks (Blackpool)
Alan Hutton (Aston Villa)
Shaun Maloney (Wigan Athletic)
David Marshall (Cardiff City)
Allan McGregor (Besiktas)
James Morrison (West Bromwich Albion)
Charlie Mulgrew (Celtic)
Steven Naismith (Everton)
Matt Phillips (Blackpool)
Jordan Rhodes (Huddersfield Town)
Robert Snodgrass (Norwich City)
Andy Webster (Heart of Midlothian)