Sentence:  Other <WSD>erstwhile</WSD> stalwarts are also wavering. Southampton had two of the best full-backs in the league last season but Ryan Bertrand has been below par this season and Cédric Soares made an uncharacteristic lapse that led to Stoke's winning goal in Southampton's last outing. 
Meaning of the word marked with <WSD> tags:  Former, previous.