Jonathan Dos Santos in talks to join his brother Giovani with LA Galaxy - source

The LA Galaxy are negotiating a contract with Villarreal midfielder Jonathan Dos Santos to become the club's third designated player, a source has told ESPN's Taylor Twellman.

If a deal is completed, Dos Santos would join his brother, fellow Mexico international Giovani Dos Santos, at the StubHub Center.

Signing Jonathan Dos Santos would also likely rule out any potential move for the Galaxy to add free agent Zlatan Ibrahimovic after he recovers from a knee injury. A source told ESPN FC in March that LA had offered the striker a deal.

Dos Santos sat out training on Monday, according to El Mediterraneo, which reported Villarreal had an agreement in principle for the player to pay a transfer fee around €5-6 million ($5.8-7m).

The 27-year-old was due back in Villarreal training after a two-week break following the Confederations Cup, but the club gave him an extra few days off to negotiate his deal with the Galaxy, the Spanish newspaper reported.

The Galaxy already have two other designated players in Romain Alessandrini and Jelle Van Damme, who both signed DP deals before the season.

But multiple reports in the offseason said that Van Damme's news contract, which pays him a base salary of just $600,000, would only be a DP deal until July 15, before being bought down with targeted allocation money. That frees up LA to find another big signing in the summer transfer window for the team's third allocated DP slot.

Villarreal already have a replacement for Dos Santos lined up as Malaga midfielder Pablo Fornals paid his own €12m release clause earlier on Monday, ahead of signing a reported five-year deal.

Dos Santos, who scored two goals with three assists in La Liga last season, previously played with his brother at the Barcelona academy before Giovani signed for Tottenham in 2008.

The two were then reunited at Villarreal when Jonathan left Barcelona to join Villarreal in 2014, where his brother had moved a year earlier. Giovani, who is a year older, then left for the Galaxy in 2015.

The Galaxy have struggled in their first season under coach Curt Onalfo, after Bruce Arena left to lead the U.S. national team in November. They are just three points above the bottom in the Western Conference with six wins from 20 games and have lost five straight in MLS.