Crist welcomed Messina to the team in a tweet Monday night.
RT to help me welcome @Messina2012 to the People's Team. Join us at http://t.co/ayqK33oCzS.
— Charlie Crist (@CharlieCristFL) January 21, 2014
Crist didn't identify what Messina's role in his campaign would be. His former campaign manager, Bill Hyers, abruptly quit in December.
But Messina is expected to act more as a senior advisor to Crist rather than a campaign manager, according to the Miami Herald. In a previous interview with the Herald, Messina had "clearly expressed his support and admiration for Crist," who switched to the Democratic party after identifying as a Republican and then an Independent.
Crist's campaign also announced it brought on the digital director for Obama's 2012 campaign, Teddy Goff, according to the Herald.
Last month an internal poll from current Florida Gov. Rick Scott's (R) camp showed Crist with a 4-point lead in a hypothetical matchup.
This post has been updated.