Fabrizio had a decorated career with the Xerox Ducati team between 2008 and 2010, a period in which he won four races culminating in a third place overall in 2009 behind Ben Spies and Noriyuki Haga.
He has also ridden Suzuki, BMW, Aprilia, Honda and Kawasaki machinery, but found himself without a permanent ride at the start of the season.
"I am very happy for this 'call' from the Althea Team," he said.
"Although it will be for just one round I am enormously proud to be working in a team that I have always aspired to be a part of. I know that I have the trust of both the Team Owner Genesio Bevilacqua, with whom I also have a very good personal relationship, and the team members with whom I worked with back in 2005.
"It will be a very exciting experience for me, full of expectation being aware that I can finally show all my worth as a complete and competitive rider. Whatever happens, it will be a success."
Fabrizio also raced with the Althea team at Supersport level back in 2005 and team owner Bevilacqua was clearly elated with the return of a veteran with 217 WSB starts to his name.
"Michel Fabrizio is one of the riders who has always gravitated around the Althea Team. Way back in 2005 he had already ridden for our Supersport team; at that time he was only nineteen and he was already giving a hard time to well-known riders such as Muggeridge, Foret and Fujiwara," Bevilacqua said.
"Today all of the Althea Team welcomes him with great anticipation. At the same time, we wish a prompt recovery to Nico Terol who, for one round, will be watching on television."