The pair – released by their respective clubs at the end of last season – are currently training with the Magpies with a view to a permanent contract here.
An England under-19’s international, the young defender-cum-midfielder has been a regular in the Blades’ reserve side, although has struggled to break into the first team at Bramall Lane.
Needham, however, dwells in the blue side of the city, with the striker having recently been released – along with recent Notts signing, Lewis McMahon – by Paul Sturrock in his drastic squad shake-up.
The striker, 19, comes with no league experience to date, although has turned out for Wednesday in LDV action.
The duo join fellow trialists Stacey Long and Jake Sheridan in the hunt for a contract at Meadow Lane ahead of the new season, now just nine days away.