Neither side have clutched that trophy before, and the Mexicans have the upper hand after a 2-1 home victory against the Black and Gold in the opening leg on Wednesday.
Match preview
LA have 90 minutes to try and find a way back into their CCL tie after being a step behind Leon throughout the opening half in Mexico.
The Los Angeles goal deep into stoppage time of that encounter does nothing more than close the gap between themselves and La Fiera, as away goals do not apply in the final of this competition.
Since losing at home in the second leg of their Round of 16 tie versus Alajuelense, the Black and Gold have outscored their last two CCL opponents 6-0 at BMO Stadium, but they have captured just one of its previous three matches played there in all competitions.
Those previous lopsided CCL victories should clearly indicate that this tie is far from over, while Steve Cherundolo's men have reversed their share of deficits over the past year.
In its three previous encounters on American soil versus Mexican sides in this competition, LAFC have come out on top every time, including a 3-0 victory at home to Leon in 2020.
In need of a victory to have a chance at winning the title for the first time, it will be interesting to see how aggressive they are from the opening whistle as they tend to be more dangerous on the counter while often catching their opponents in transition down the left.
Job one is complete, and aside from the late goal conceded, Nicolas Larcamon could not have been much happier with his team's performance at home in the opening leg.
His players were on the front foot for most of the opening half, and when facing a surge from LAFC in the final 45 minutes, they remained disciplined and patient at the back, halting most of their opponents' attacks.
Perhaps a good omen for Leon is that the last four CCL clubs to win the final's opening leg have gone on to claim the title, while no team has reversed a second-leg deficit at this stage of the competition since Pachuca in 2010.
Leon, meanwhile, have gone on to win their two previous Champions League ties when leading after the opening game, though, since late April, they have gone on to lose two matches in which they have drawn first blood, the last one being at home to San Luis in Liga MX in early May (3-1).
They have only captured one away fixture versus a Major League Soccer opponent, crushing Sporting Kansas City 6-1 in the 2021 Leagues Cup quarter-final from Children's Mercy Park.
Los Panzas Verdes have only suffered one defeat in the Champions League this season, winning their last four matches in all competitions when leading at the interval.
Los Angeles FC CONCACAF Champions League form:
Los Angeles FC form (all competitions):
Club Leon CONCACAF Champions League form:
Club Leon form (all competitions):
Team News
Jesus Murillo, Kellyn Acosta and Giorgio Chiellini all missed the opening leg of this clash for LAFC with pain in their lower extremities, Tony Leone is unlikely to feature because of a right leg injury and Maxime Crepeau will not be available as he is still nursing a broken leg.
Regardless of how Sunday's match finishes, Denis Bouanga is likely to be named top scorer, notching his seventh of the competition in the 96th minute on Wednesday, while Carlos Vela has two goals in his LAFC career versus Leon, both coming in their 3-0 home victory against the Mexicans in this competition in 2020.
John McCarthy has four clean sheets at this tournament, while Timothy Tillman, Kwadwo Opoku and Bouanga each found the back of the net in their second-leg semi-final triumph versus the Philadelphia Union.
David Ramirez was not available for Leon on Wednesday as he remains out with a hip flexor, Jose Rodriguez is listed as doubtful due to a knee injury, while there were two newcomers in the starting 11 who did not begin their second-leg clash with Tigres as Yairo Moreno and Ivan Moreno replaced Byron Castillo and Elias Hernandez.
William Tesillo put them in front after eight minutes earlier this week, his first of the tournament, with Angel Mena adding some insurance from the penalty spot late in the opening half, his third of the competition, moving into a tie for the team lead alongside Victor Davila.
Their last two away goals in this competition came courtesy of Davila in the semis and Brian Rubio in the previous round at Violette, while Rodolfo Cota has three clean sheets in the Champions League, including one on the road versus Tauro in March (1-0).
Los Angeles FC possible starting lineup:
McCarthy; Hollingshead, Maldonado, Long, Palacios; Biuk, Sanchez, Cifuentes; Opoku, Vela, Bouanga
Club Leon possible starting lineup:
Cota; Barreiro, Frias, Tesillo; I. Moreno, Ambriz, Romero, Y. Moreno; Mena, Davila; Alvarado
We say: Los Angeles FC 1-0 Club Leon(Los Angeles FC wins on penalties)
That late goal on Wednesday should give LA hope heading into this leg after struggling to find a lot of openings against a well-organised Leon side.
Expect the game plan to be similar for the Mexicans, however, we believe the LAFC attack will find a way through this weekend, having faced adversity in big games before, while McCarthy has been an X-factor in penalty shootouts.