It is the first competitive meeting between the two sides since 2015, when Cardiff ran out 3-1 winners in the FA Cup.
Match preview
Cardiff exited the EFL Cup at the first round stage in the 2022/23 campaign, losing 3-0 to Portsmouth at the beginning of what was a very disappointing season, only just managing to avoid relegation from the Championship.
The Bluebirds finished just five points above the bottom three, only surviving as a result of Reading's six-point deduction, and new manager Erol Bulut will be eager for his side to kick on this season.
It was a mixed pre-season for Bulut's side, picking up victories against the sides they were expected to beat, namely Penybont and The New Saints, however they came up short against FC Porto and Braga in their pre-season tour of Portugal.
In their opening Championship game, Cardiff got off to a brilliant start away at recently-relegated Leeds United, with Josh Bowler and Ike Ugbo scoring first-half goals to ensure they went in two goals to the good at the break.
However, Leeds roared back in the second half, with Liam Cooper scoring an early goal, before Crysencio Summerville bagged a 95th-minute equaliser, denying Bulut a victory in his first competitive game in charge.
Although their opponents did not kick off with a win in the Championship, Colchester United will still have their work cut out on Wednesday night, considering they are currently plying their trade two divisions lower, in League Two.
Colchester also only just managed to avoid the drop last season, finishing 20th in the fourth tier, six points clear of the bottom three, but they will be eager to demonstrate they have improved by kicking off their campaign with a surprise victory at the Cardiff City Stadium.
The U's' season should have commenced on Saturday afternoon, but their opening game against Swindon Town was postponed due to a waterlogged pitch, meaning they have not been in action since an impressive 2-1 victory against League One Leyton Orient at the end of July.
Results in pre-season always have to be taken with a pinch of salt, but Colchester did well to overcome the odds and defeat last season's League Two winners, with Connor Hall getting on the scoresheet, and it should give them confidence heading into a tough game on Wednesday.
Cardiff City form (all competitions):
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Colchester United form (all competitions):
Team News
Cardiff midfielder Joe Ralls went off injured in the first half during their 2-2 draw against Leeds at the weekend, meaning he is unlikely to be risked on Wednesday night, with Ebou Adams poised to come into the starting lineup.
Bulut was likely to make a few changes regardless of any injuries, considering his side are coming up against lower-league opposition, and Yakou Meite could replace Karlan Grant at striker, while new-signing Andy Rinomhota may come in for Aaron Ramsey in central midfield.
Colchester were unable to get their opening League Two game on at the weekend, but they had already announced their starting lineup, with Tom Hopper and Samson Tovide being named as the starters in attack, and the duo are likely to lead the line.
Given the difficult of the task on Wednesday night, manager Ben Garner may name his strongest XI, with captain Hall, Tom Dallison and Nico Lawrence starting in central defence, while Junior Tchamadeu and Ellis Iandolo should get the nod at full-back.
Mauro Bandeira, Arthur Read and Noah Chilvers should feature in midfield, with the latter in particular playing provider for Hopper and Tovide.
Cardiff City possible starting lineup:
Alnwick; Romeo, McGuinness, Goutas; Bowler, Wintle, Adams, Rinomhota, O'Dowda; Etete, Meite
Colchester United possible starting lineup:
Goodman; Tchamadeu, Lawrence, Dallison, Hall, Iandolo; Read, Bandeira, Chilvers; Tovide, Hopper
We say: Cardiff City 2-0 Colchester United
Although they were denied all three points by a last-minute equaliser, Cardiff showed some very promising signs against Leeds last week, and we expect them to breeze through on Wednesday night.
Colchester were very poor in League Two last season, and while it is difficult to gauge whether they have improved since then, they are unlikely to win away against a team two divisions above them.