Mario Martinez took to Twitter on December 26th to tell all his followers that he is coming to Seattle soon.
Mi retorno a Seattle esta mas cerca..— Mario Martinez M10M (@mariomartinez_7) December 26, 2013
Now, he is talking about it with Honduran media, where he gives his return about an 80% chance. With Real Espana he won the Apertura title playing in 20 of their 23 total matches. The start of the season was a bit rocky, but he ended with six goals in league competition.
He did lose his role with the national team. He states in the linked story from Diez that he wants to earn his way to Brazil. Martinez also notes that he got into a slump in midseason and that's something he needs to avoid in 2014.
Mario would be a replacement (half a replacement since he started 2013 here?) for the creativity lost during the flurry of offseason moves. There is no indication if his move would be permanent or a fourth loan from Real Espana (second to Seattle).
If Seattle Sounders FC sticks with the diamond he could start as the left mid while providing depth on the right and at CAM.