The Blues have announced the striker is joining on loan until the end of the season – on the same day that John Marquis’ departure was revealed.
The 25-year-old becomes the club’s second January signin, after Hayden Carter’s arrival from Blackburn last week.
A new front man has been a priority for Danny Cowley this winter, with the Fratton Park side struggling for goals this term – and he’ll hope the former Nottingham Forest man can rectify the problem.
In total, Walker has bagged 11 goals in 52 appearances for Mark Robbins’ side, but has fallen down the pecking order this term.
That has opened the door to a temporary departure from the Coventry Building Society Arena this month.
He’ll reunite with Cowley for the first time, with the pair working together at Lincoln in 2019.
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