The Spaniard has been in fine form since his arrival from Valencia in the summer and helped Albion to four wins out of four during September; missing the side's only defeat to Birmingham City.
Albion conceded just two league goals with Bruno playing an integral role at right-back, and the 32-year-old also showed off his attacking qualities when he provided two assists in the 3-0 win over Sheffield Wednesday.
The Spanish defender has been shortlisted for the award alongside former Albion striker Glenn Murray (Crystal Palace) and Wes Morgan (Leicester City).
The winner of the award will be announced on Friday.
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