The frontman spent the latter part of the 2018/19 campaign on loan with Ebbsfleet, managed by his old Woking boss Garry Hill.
READ: Ugwu reveals his Proact frustrationIt was a prolific season with Woking that earned him a move to then League Two Chesterfield in 2017, when he penned a two-year deal.
But injuries devastated his first season and despite being talked up by former Town boss Martin Allen last summer, the 6ft 2ins forward was farmed out on loan to Boreham Wood by September.
When that loan deal was ended by Boreham Wood in March, Ebbsfleet, who previously had him in the 2011/12 season, took him until the end of the campaign.
Ugwu was released by John Sheridan this summer, after 21 appearances and no goals as a Spireite.