The West Ham official website has this afternoon revealed that the Olympiakos game is on,
"The match was in doubt after the Greek team encountered problems with travelling to Britain after the security alerts brought to light yesterday. However, West Ham officials have been working hard with Olympiakos to overcome those issues with success and the Greek team are now due to take a later flight this evening and the match will kick-off as planned at 3pm tomorrow.
Should the situation change West Ham supporters will be informed immediately via the official website but we are confident this will not be the case and look forward to staging the friendly as planned.
Tickets will be available to purchase on the day with prices starting at £15 for adults and £5 for concessions."