Bristol City will be without Ivan Sproule for the visit of managerless Reading.
The winger pulled up with a hamstring strain just before half-time during the 1-0 defeat at Doncaster on Saturday and faces up to three weeks on the sidelines.
Gavin Williams replaced Sproule last time out and is the most likely player to deputise in his absence.
Evander Sno is set to return from suspension but it remains to be seen whether captain Louis Carey will be back after a groin problem.
Johnson otherwise has a full-strength squad to choose from as the Robins look to improve on their recent run of form that has seen them win just one of their last seven league games.
Brian McDermott will take the reins for the first time when Reading visit Ashton Gate.
The Royals' chief scout has been placed in charge of first-team affairs following the departure of manager Brendan Rodgers.
Rodgers left the club by mutual consent on Wednesday evening after little more than six months in charge, with first-team coach Dean Austin and football consultant Frank Lampard Sr following suit.
McDermott will be able to welcome back Shane Long after a three-match suspension, while fellow striker Simon Church is hoping to recover from a back injury in time to face the Robins.
Ryan Bertrand is also hoping to return to the fold after missing last weekend's 1-1 home draw with Scunthorpe through illness.
However, Reading will be without long-term absentees Noel Hunt (knee) and Brian Howard (jaw).
Copyright (c) PA Sport 2009, All Rights Reserved.