The Pompey manager issued the clear instruction after substituting the defender during the second half of Saturday’s 2-1 defeat at Sunderland.
Walkes was replaced at right-back on 73 minutes by on-loan Rangers midfielder Ross McCrorie, as the Blues attempted to improve their attacking threat from wide areas.
The switch worked, with McCrorie catching the eye during his cameo appearance in an unfamiliar role.
But it wasn’t enough to prevent Pompey suffering a second successive League One defeat on the road this term.
Walkes has been replaced in both those losses – against Shrewsbury and the Black Cats – after Jackett identified the full-back role as a key route to strengthening his side’s threat going forward.
And amid calls on social media for McCrorie to replace the former Spurs and Atlanta United defender in the side for Tuesday night’s visit of Coventry, the manager has tasked the player to work hard on developing his game in the attacking third of the pitch.
Jackett said: 'For Anton, I've brought him off twice, obviously – the two away games we've played against Shrewsbury and Sunderland.
'I think he's been pretty solid defensively, but then coming out with the ball, when he's been our spare man a couple of times, we just haven't had enough going forward and for him anyway he has to keep going.
‘He's got good athleticism and solid defensiveness, but as he progresses throughout his career, (he needs to) work hard at making the right decisions with the right quality.’
Jackett confirmed Walkes was available for selection ahead of the Coventry game.
However, with James Bolton closing in on a Blues return following an ankle injury, and McCrorie’s display at Sunderland, the manager admitted he’s got options if he wanted a change in personnel.
'He (Walkes) is 100-per-cent fit and has no problems,’ added Jackett.
'James Bolton is a little bit closer and with every few days training I do feel more towards 100 per cent for that ankle, which is good news.
'And obviously Saturday I put on Ross McCrorie there, so I do feel there's options, with Anton being one of the three.'