"We were planning on moving the training ground to Rush Green at the end of the season, now we are moving that forward," the Croatian told reporters at his pre-match news conference.
"We will be training at Rush Green from Monday. The pitches here at Chadwell Heath are soft on top, but hard underneath which is the worse combination. So I have made the decision to go to Rush Green where the pitches are better.
"This is not the fault of the groundsmen or the medical staff, it is just a fact."
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Reid joins Victor Moses (hamstring), Manuel Lanzini (thigh), Diafra Sakho (thigh), Enner Valencia (ankle) and Dimitri Payet (ankle) on the sidelines.
"Winston's injury doesn't look good. We don't know how long he'll be out for yet, we'll know more tomorrow after the scan," Bilic said.
"He slipped early on in the training session, it looks like a rupture. He'll definitely be out of the Stoke game and a few more games.
"We are now missing six very important players, but we can't complain."
Bilic said he expected Lanzini to return in time for the visit of Swansea City on Dec. 20 while Payet and Valencia are also approaching full fitness.
West Ham sit seventh in the table, but are without a win in their past five league games, stretching back to Oct. 31, while 11th-placed Stoke, who are just a point behind the Hammers, beat Manchester City 2-0 in their last league outing.
(Reporting by Simon Jennings in Bengaluru; editing by Sudipto Ganguly)
