The Irons host Bournemouth in what will be the first ever Premier League game at the Stratford-based arena this evening.
It is something of a momentous day for West Ham and plenty of club legends - including Sinclair - will be in attendance.
But the 43-year-old has suggested on Twitter that he has mixed feelings about the stadium by describing his opinion as 'love/hate'.
The Hammers boast a 100% record at the new ground after winning their one and only match 3-0 against NK Domzale in a Europa League qualifier earlier this month.
But Bournemouth could spoil the party this evening. They looked a very good side against Manchester United last week, in spite of a 3-1 defeat, and nobody in claret and blue will be taking the Cherries lightly today - they can't afford to.
West Ham lost their opening game of the season after losing 2-1 at London rivals Chelsea on Monday night, albeit in controversial circumstances, but Slaven Bilic will be determined to put things right on their OS coronation.