The 27-year-old defenseman had signed a one-year contract with Edmonton on Aug. 20 after winning the Stanley Cup with the Washington Capitals.
Jerabek has eight points (two goals, six assists) in 36 NHL games with the Montreal Canadiens and Capitals. He had one assist in two Stanley Cup Playoff games last season.
The Blues begin the 2018-19 season against the Winnipeg Jets at Enterprise Center on Thursday (8 p.m. ET; FS-MW, TSN3, NHL.TV). The Oilers open against the New Jersey Devils at Scandinavium in Gothenburg, Sweden, in the 2018 NHL Global Series on Saturday (1 p.m. ET; NHLN, SN, MSG+, NHL.TV).