The pick becomes a fifth-rounder in 2020 if Jerabek appears in 50 or more regular-season games for St. Louis this season. General manager Doug Armstrong announced the trade Monday on the eve of the deadline for NHL teams to set their opening night rosters.
The 27-year-old Jerabek won the Stanley Cup with the Capitals last season after playing in 11 regular-season and two playoff games for Washington. He was not expected to make the Oilers' roster.
In 36 career games with the Montreal Canadiens and Capitals last year as a rookie, the Czech native has two goals and six assists. He could fit on St. Louis' blue line for its Thursday game against Winnipeg with Robert Bortuzzo suspended for a hit to the head of Washington's Michal Kempny.