Forward Alex Galchenyuk has been placed on injured reserve.
Johnson, 25, played in the WBS Penguins' season opening win against the Hershey Bears on Saturday and recorded two assists.
In his lone preseason appearance with Pittsburgh this season, Johnson scored a goal and was plus-2 against the Buffalo Sabres on September 16.
Last season, the Grand Rapids, Minnesota native played six NHL games with the Penguins, collecting two assists and finishing plus-2. Both helpers came during the Penguins' 3-1 win on March 31 against the Carolina Hurricanes. Johnson also appeared in 67 games for WBS in 2018-19, finishing fourth on the team with 43 points (18G-25A).
The 6-foot, 174-pound forward has skated in 138 career AHL games, recording 29 goals, 47 assists and 76 points.
The undrafted college free agent initially signed with the Penguins after attending the teams prospect development camp on a tryout contract during the summer of 2017.
Pittsburgh concludes its season-opening four-game homestand tomorrow against the Anaheim Ducks at 7:00 PM ET at PPG Paints Arena. The Penguins will embark on their first road trip of the season this weekend with back-to-back games in Minnesota and Winnipeg on Saturday and Sunday.
