Johnston was scratched in Thursday's 2-1 overtime loss to the Penguins, the sixth time in 10 games he's been in the press box.
Johnston recorded two hits and a fighting major in Thursday's 4-0 win over the Blackhawks.
Johnston played in Thursday's 1-0 loss to the Blackhawks, logging one shot on goal, one hit and one blocked shot in 7:35 of ice time.
Johnston logged an assist and five PIM in Saturday's 7-4 win over the Flyers.
Johnston logged an assist, two shots on goal, two hits and two PIM in Tuesday's 3-2 overtime win over the Blue Jackets.
Johnston was claimed by the Ducks on Tuesday after being waived by the Islanders on Monday, Elliotte Friedman of Sportsnet reports.
Johnston was placed on waivers Monday, Chris Johnston of TSN reports.
Johnston was a healthy scratch as the Islanders defeated the Red Wings 4-1 on Saturday.
Johnston was a healthy scratch in the 6-5 loss to the Canucks on Thursday.
Johnston has been a healthy scratch for the past two games.