Messi has an outstanding record against Sociedad, netting 15 goals and recording eight assists in just 20 matches against them across all competitions.
However, Imanol believes that the mentality of such a decorated player does not suit the sort of culture he is trying to create within his own side.
"He wouldn't fit with the values and the way we are at Real Sociedad," Imanol told Marca.
"However, he's an incredible player and does incredible things.
"But these values of humility, normality, these big players don't have them, coaching Messi would give me headaches, even though I'd win more games."
Messi hit 36 goals and set up 15 more in his 34 league appearances last season, contributing directly to 51 of the club’s 90 league goals as he dragged Barca to another La Liga title.
However, the goals are shared around a little more in Imanol’s side. Mikel Oyarzabal, Willian Jose and Martin Odegaard are the only three players to have scored more than once, while four others have a solitary strike to their name.
Despite that, just three points separate Sociedad – fifth in La Liga – from reigning champions Barca in second.
Ernesto Valverde’s side have suffered as Messi battled with injury at the start of the season, losing to Athletic Bilbao and Granada and drawing with Osasuna in three of their first five league games.
However, Messi completed 90 minutes in the Blaugrana’s 2-1 Champions League win over Inter, registering an assist, before making a goalscoring return to league action as he played the entirety of the 4-0 win against Sevilla.
Sociedad take on a struggling Real Betis side next as they hope to close the gap to the top two, with their opponents just two points clear of the relegation zone.
Barcelona face an Eibar outfit in the same situation as Betis in La Liga and will expect to win with Messi back in the side as they look to pile the pressure on unbeaten league leaders Real Madrid, who are two points ahead of them.