Player-manager Sean Ray begins a four-match ban following his red card against Peacehaven & Telscombe in the previous round two weeks ago.
Midfield pair Jamie Crellin and Tom Vickers will also be missing as they both begin two-game suspensions having picked up 10 yellow cards.
Sam Adams is cup-tied having featured in the same competition for Rye United before his transfer back to Hastings last week.
Crawley were in League One action last night against Brentford, going down 2-1. They will obviously field a much-changed side, with the club’s website stating ‘tonight’s line-up will be a mixture of pros and youth team players’.
Defender Kyle McFadzean is expected to return after a three-month absence due to a virus, while Jonte Smith, Aiden O’Brien and Johnny Maddison are all set to be involved too.
Only one side has advanced to the last four of the competition so far. United’s Ryman Football League Premier Division rivals Bognor Regis Town saw off Blue Square Bet South club Eastbourne Borough 3-1 last night.
The two other quarter-finals - Brighton & Hove Albion versus Three Bridges and Eastbourne Town against East Preston - are scheduled for next month.
United’s game tonight marks an almost ten-year anniversary since one of the last meetings between the sides before Crawley continued their assault towards the Football League.
The teams drew 1-1 at Crawley’s Broadfield Stadium on February 25, 2003 in a Southern League Premier Division game, with United’s goal coming from Zahana-Oni Landry. Kick-off at The Pilot Field tonight is 7.45pm.