Dimas is set to be unveiled as the Western Sydney Wanderers' third A-League captain and the first foreign player to take on the role.
It's understood the Spanish midfielder, who has been wearing the armband temporarily, will permanently fill the vacancy left by recently departed skipper Nikolai Topor-Stanley.
Dimas led the Wanderers in both their first- and second-round matches against Sydney FC and Adelaide United while Topor-Stanley was suspended and then in Dubai sealing his transfer to UAE Pro League outfit Hatta.
Now he will become just the third captain in the club's fifth season, following in the footsteps of Topor-Stanley and inaugural skipper Michael Beauchamp.
With the players on a day off on Thursday, the club is expected to announce the appointment on Friday.
Dimas is only beginning his second season with the Wanderers but was a midfield standout in last campaign's grand final run alongside fellow Spaniard Andreu, who left in the off-season due to a contractual impasse.
The 33-year-old also has the experience required, with more than 200 caps in Spain's top two divisions.
His appointment will follow that of Uruguayan striker Bruno Fornaroli as Melbourne City captain, the pair joining Central Coast's Scottish skipper Nick Montgomery as the only imports to lead A-League clubs.