Yarmolenko, who can operate as a forward or as a winger, has undergone surgery to repair a damaged Achilles tendon.
The 28-year-old Ukraine international suffered the injury during West Ham’s 1-0 defeat to London rivals Tottenham Hotspur at home in the Premier League at the weekend.
West Ham co-chairman Gold has stated on Twitter that he will personally convey messages of support to the 28-year-old attacker - who joined the Hammers from German club Borussia Dortmund in the summer transfer window for a fee reported by Sky Sports to be worth £17.5 million - with some fans of the London club responding to his message on the social networking site.
Yarmolenko has made five starts and four substitute appearances in the Premier League for West Ham so far this season, scoring two goals in the process, according to WhoScored.
Andriy Yarmolenko’s has undergone surgery to repair a damaged Achilles tendon and is expected to be sidelined for around six months.— David Gold (@davidgold) October 22, 2018
I will personally let him know that we will all support him through this difficult time and we all wish him a speedy recovery. dg @Yarmolenko_9 pic.twitter.com/cUfp9Rpwji
Does this mean more investment in January as we are clearly lacking in some areas... Also it would be nice if we could get this Rice situation sorted so we can all have a nice Christmas. The lad is a proven key player so let’s just pay him what he’s worth ay?— Jay Jamieson (@jay_jamieson) October 22, 2018
Really sad to hear a player is out for so long for any team, hope he recovers soon enough— Ang (@1containment) October 22, 2018
Great gesture mr gold. Signs of progress— Laudable Lanzini (@LaudableLanzini) October 22, 2018
We need another CAM asap. Really sorry for Yarmo, hope for a speedy recovery but it will be very very difficult. By the way, WE ARE WEST HAM UNITED AND WE NEVER GIVE UP ⚒⚒⚒ #COYI— Matteo Rovai (@Matte_Rova) October 22, 2018
The timing could not be worse but hey we push on. Get back soon Yarma you are well liked by us lot— Freddies shears (@thatlldopigthat) October 23, 2018
Shame, loved what I’ve seen so far. Seems to be very happy at the club.— LasVegasWestHamUtd (@WestHaminVegas) October 22, 2018
We will miss you Andriy, all the best and look forward to seeing you back in action soon— Mark Honeybourne (@HoneybourneMark) October 23, 2018
Get well soon Andriy, you will be missed. Six months will go quickly, you will be back fitter and better. CÒYI ⚒⚒⚒— Iain Tait (@RitaitIain) October 23, 2018
Great message @davidgold , gutted for the lad though - had really started to make an impact— Glen Gallogly (@Glen1540Glen) October 22, 2018