The 30-year old centre-back has been brought in for the rest of the season to help with the Hammersâ€™ injury crisis after spending the first half of the campaign with Sheffield Wednesday.
An official West Ham statement read: "West Ham United are pleased to confirm the signing of centre-back Roger Johnson on loan for the remainder of the 2013/14 season."
In addition, Jack Sullivan, the son of co-chairman David Sullivan, posted the following on Twitter.
ROGER JOHNSON has signed till the end of the season, as emergency cover at CB. He might surprise a few people. More news soon
— Jack Sullivan (@jsullivanwhu) January 6, 2014
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