The Robins are going through a horrible run of form, and another loss in midweek would make it five defeats on the bounce in the league. This is something manager Dean Holden desperately needs to avoid.
That being said, his counterpart Veljko Paunović also needs to win to stay in the playoff spots.
Reading have only had one win from their last five outings, and will drop out of the top six if they don't find their mojo back soon. Clearly, this is a massive game for both sides.
Bristol City vs Reading head-to-head
The two teams will meet for the 100th time on Tuesday evening, making it a landmark result for the victorious side.
Historically, this match-up has proved very difficult to predict. Bristol City have won 39 games, one less than Reading's tally of 40. The reverse fixture this season saw the Royals win 3-1, and they will hope to draw inspiration from that result.
Bristol City form: L-L-L-L-W
Reading form: L-L-D-W-D
Bristol City vs Reading team news
Alfie Mawson served a one-match suspension against Watford. Dean Holden will be relieved to have the former Swansea man back, especially considering how the team struggled in his absence.
Veteran centre-back Adrian Mariappa came off the bench against Watford, and could be handed a start in midweek.
Injuries: Andreas Weimann, Steven Sessegnon
Reading's lack of squad depth has hurt them severely amid the injury-crisis they are facing.
Young fullback Tom Holmes could be replaced by Andy Yiadom in the starting lineup, but Veljko Paunović is unlikely to make many more changes.
Injuries: Yakou Meite, John Swift, George Puscas, Liam Moore
Bristol City vs Reading predicted XI
Bristol City predicted XI (3-5-2): Daniel Bentley; Adrian Mariappa; Alfie Mawson; Tomas Kalas; Ryley Towler; Han-Noah Massengo; Henri Lansbury; Jamie Paterson; Jack Hunt; Nahki Wells; Famara Diedhiou.
Reading predicted XI (4-2-3-1): Rafael Cabral; Andy Yiadom; Michael Morrison; Tom McIntyre; Lewis Gibson; Alfa Semedo; Josh Laurent Michael Olise; Andy Rinomhota; Ovie Ejaria; Lucas Joao.
Bristol City vs Reading prediction
It is really tough to envisage Bristol City winning a game of football at the moment. They are shambolic at the back and toothless going forward.
Reading have also struggled of late, but the Championship's third-highest scorer Lucas Joao could carry them to a hard-fought victory.
Prediction: Bristol City 1-2 Reading