Four defeats in their last five league matches have place Welsh in 10th place in the table, while their opponents this weekend are one place below thanks to just two wins in nine.
The hosts have named an unchanged lineup from the side that lost 23-16 to Northampton Saints last weekend.
London Welsh: WLWLLL
London Irish: WWLWWL
London Welsh: Arscott, Caprice, Parker, Tonga'uiha, Scott, Ross, Keats, Montanella, Briggs, Ion, Mills, Kulemin, Browne, Jackson, Balding
Replacements: Bateman, Bristow, Tideswell, Corker, To'oala, Stevenson, Davies, Jewell
London Irish: Homer, Ojo, Tagicakibau, Geraghty, Watson, Humphreys, Allinson, Lahiff, Blaney, Halavatau, Skivington, Evans, Danaher, Garvey, Hala'ufia
Replacements: Ellis, Yanuyanutawa, Aulika, Low, Sinclair, Gibson, Shingler, Moates
Sports Mole says: Irish to earn a rare victory