The sides are locked level after the first leg at Stamford Bridge, which finished 1-1, and they will be doing their utmost to ensure their place in the quarter-finals.
With home advantage and an away goal under their belts, Barca come into the game in a better position than the Blues, but Antonio Conte's men will be undeterred.
However, the Catalan giants also boast a vastly superior set of recent results, going unbeaten in the last 14 matches in all competitions, while Chelsea have lost two of their last five.
|Game||Barcelona vs Chelsea|
|Date||Wednesday March 14|
|Time||19:45 GMT / 14:45 ET|
|Stream (US only)||fubo TV (7-day free trial)|
TV Channel & Live Stream
In the United States (US), the game can be watched live and on-demand with fuboTV (7-day free trial).
New users can sign up for a free seven-day trial of the live sports streaming service, which can be accessed via iOS, Android, Chromecast, Amazon Fire TV, Roku and Apple TV as well as on a web browser.
|US TV channel||Online stream|
|Fox Sports 1||fubo TV (7-day free trial)|
In the United Kingdom (UK), the game can be watched live on TV on BT Sport 2 and it can be streamed live online using the BT Sport app.
|UK TV channel||Online stream|
|BT Sport 2||BT Sport app|
Squads & Team News
|Goalkeepers||Ter Stegen, Cillessen, Ortola|
|Defenders||Semedo, Pique, Alba, Digne, Vidal, Umtiti, Mina, Vermaelen|
|Midfielders||Rakitic, Iniesta, Busquets, D. Suarez, Paulinho, Roberto, Gomes, Alena|
|Forwards||L. Suarez, Messi, Dembele, Alcacer, Arnaiz|
Messi returns to the squad having missed Barca's last game for the birth of his third child, while Andres Iniesta took part in training on Monday and could be involved.
Nelson Semedo remains sidelined with an injury, while Philippe Coutinho is cup-tied because of his previous involvement in this season's competition with Liverpool.
Potential Barcelona starting XI: Ter Stegen; Vidal, Umtiti, Pique, Alba; Rakitic, Busquets, Iniesta; Suarez, Dembele, Messi.
|Goalkeepers||Caballero, Courtois, Eduardo|
|Defenders||Rudiger, Alonso, Zappacosta, Cahill, Christensen, Azpilicueta, Luiz, Emerson, Sterling|
|Midfielders||Fabregas, Drinkwater, Kante, Barkley, Hazard, Pedro, Bakayoko, Moses, Willian, Scott|
|Forwards||Morata, Giroud, Hudson-Odoi|
Chelsea are likely to be without defender David Luiz, who is recovering from an ankle injury, while Ross Barkley remains sidelined with a hamstring issue.
Potential Chelsea starting XI: Courtois; Rudiger, Christensen, Azpilicueta, Alonso, Zappacosta; Kante, Fabregas, Hazard, Willian; Morata.
Betting & Match Odds
Barcelona are 8/15 favourites to win the match and 2/9 to qualify for the quarter-finals according to dabblebet, while Chelsea are priced at 5/1 to win the game and 3/1 to progress.
A draw between the teams, which, depending on the score, could see either side qualify for the next round, is a 16/5 bet.
When the sides met in the first leg back in February, Chelsea, and Willian in particular, looked to have the measure of Barcelona, but Messi responded to the Brazilian's goal by breaking his Blues hoodoo to hand the Catalan giants the initiative heading into the second leg.
Since then, Conte's side have struggled, with defeats to Manchester United and Manchester City delivering a serious blow to their hopes of securing a top-four Premier League finish and thus, Champions League qualification for next season.
They improved somewhat in their last outing against Crystal Palace to claim a 2-1 win, with Willian again demonstrating the type of quality they will be relying on if they are to upset the Blaugrana at Camp Nou on Wednesday.
Given that Barca are in sensational form and the fact that they are at home, where they have not lost a game since their Supercopa defeat to Real Madrid last August, Conte is aware that Chelsea must be patient as they attempt to defy the odds.
"We must be very good but when you play against this type of team, which I think is one of the best in the world, you must be prepared to suffer, in the same way we did in the first leg, where I think we were almost perfect," the Blues boss said.
However, with Messi scoring five goals in his last four appearances and eager to continue that form, they will have to be careful not to end up suffering too much.