A report from the Evening Standard suggests that Obiang has only returned to light training, with manager Manuel Pellegrini himself explaining at his weekly press conference that the Spaniard will not feature against Leicester and will instead return in the Carabao Cup against Tottenham.
Ukrainian winger Andriy Yarmolenko was the latest to join the injury list last weekend after rupturing his achilles during the Spurs game. He was stretchered off and has since undergone successful surgery - it will likely be March or April before he is ready to return.
Yarmolenko took to Instagram this week to thank Hammers fans for the messages he has received since his injury: "I would like to say thanks for your support and wishes for my recovery. I really appreciate it."
Carlos Sanchez is another summer signing who is unavailable. The Colombian midfield shield is sidelined as a result of knee trouble after Pellegrini confirmed earlier this month that there was a 'problem with his knee ligament' suffered during the 8-0 cup win over Macclesfield.
Manuel Lanzini is also long-term absentee because of knee ligament damage, while Winston Reid is working his way back to fitness after knee trouble of his own. Andy Carroll and Jack Wilshere are much closer to returns, but are still not expected to be available until November.
After an impressive run of results against Everton, Chelsea, Macclesfield and Manchester United, the Hammers have narrowly lost 1-0 in each of their last two games. They will be hoping to end that mini streak against Leicester, while games against Tottenham in the Carabao Cup and Burnley in the Premier League are coming thick and fast as October turns into November.