Perhaps the only substantial enclave pulling for Tigres UANL in South America exists in the blue and gold sector of Buenos Aires. Boca Juniors opened their training ground to the Mexican side ahead of the second leg of the Copa Libertadores final on Wednesday night. It is a gesture rooted in hatred for River Plate, not solidarity for Tigres' quest to become the first Liga MX club to win this trophy.

At this point, Tigres will relish any sort of reluctant favor ahead of the decisive second leg at Estadio Monumental (live, 9:00p.m. ET, FOX Deportes, FOX Sports Go). This long, hard slog to the final included rigorous travel commitments back and forth and the usual tipped circumstances in favor of South American sides. The Mexican side should host this second leg after entering knockout play as the second seed, but CONMEBOL regulations dictate a South American club must stage the last match in this competition.

This structural hurdle tripped up the two previous Mexican sides to reach the final. Cruz Azul accomplished the considerable feat of winning 1-0 at La Bombonera back in 2001, but Boca Juniors won the title on penalty kicks. Chivas Guadalajara lost both legs to Internacional five years ago, but Marco Fabian's opener in Porto Alegre provided them a foothold before the home side swept through.

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Tigres hope to condemn those memories to history and secure their own legacy by emerging victorious in hostile territory. The away goals rule does not count now. The outcome of this final rests on this result alone -- whether procured in normal time or whether sorted out by extra time and potential spot kicks -- after the scoreless draw at Estadio Tecnológico a week ago.

This one-off fixture represents perhaps the best chance for a Mexican side to lift the trophy since Liga MX sides first entered the competition in 1998. River Plate enter with a raft of selection questions due to injury and suspension. Tigres gear up for the gauntlet ahead with a reinforced, seasoned squad girded for the challenge by a lavish summer spending spree bankrolled by concrete magnates CEMEX.

The Monterey-based company tapped into its considerable reserves to back manager Tuca Ferretti in the transfer market and import players capable of delivering the title. Marseille forward André-Pierre Gignac joined on a free transfer to lead the line, while Villarreal duo Javier Aquino and Ikechukwu Uche plus promising Pachuca winger Jurgen Damm further bolstered the attacking options.

Uche isn't a factor here, but the other three players -- including the fit-again Aquino (ankle) -- all look likely to feature in this organized, potent outfit. Tigres dominated most of the ball in the opening leg in its 4-4-2 shape with most of the creative responsibility falling to wingers Damm and Damian Alvarez. The speed in the wide areas -- increased by the likely return of Aquino on the left -- allows Tigres to break quickly with Gignac and Rafael Sobis plenty capable of rounding off the moves with the corresponding finish. Gignac and Sobis operate deftly enough to pose a threat in possession as well, particularly if they receive the proper service from crosses and set pieces.

Those attacking efforts do not come at the expense of the defensive shape. Egidio Arévalo Rios and Guido Pizarro form a defiant duo in the heart of midfield to keep the play moving and prevent the side from getting exposed when the fullbacks push onwards. There are defensive concerns at fullback with Israel Jimenez on the right, but Juninho and Hugo Ayala often mask those vulnerabilities in central defense. Ayala's absence due to the left ankle injury sustained in the first leg presents a real quandary for a group reliant on his steady excellence to maintain the proper cohesiveness at the back.

River Plate manager Marcelo Gallardo faces more pervasive concerns after his side failed to create much of anything in Nuevo Leon a week ago. Gallardo must alter his starting XI significantly with top scorer Rodolfo Mora and the inventive Tabare Viudez expected to miss out through injury. Their omissions strip away some of the creativity and the potency within the ranks in a match where River must shoulder more of the burden to win the Libertadores for the first time since 1996.

Gallardo must contemplate how to coax River forward intelligently without exposing the issues at right back (first leg starter Gabriel Mercado is suspended through caution accumulation, while usual deputy Emanuel Mammana is hurt). Uruguay winger Carlos Sanchez inevitably carries responsibility on the right, but the complementary figures remain in some doubt. Experienced figures Fernando Cavenaghi, Lucho Gonzalez and Javier Saviola all hope to play some part, but Gallardo needs to strike the right balance to ensure his side retains the tools necessary to blunt the counter and close space as effectively as it did in the first leg.

The three previous meetings -- two group stage draws, plus the scoreless first leg -- reflect the narrow margins likely to determine this final. There is little room for error with such formidable stakes on the line. River crave a third title, while Tigres exist in this current form to deliver Mexico's first triumph in the competition. It will take a considerable performance to end the drought at last and spark celebrations likely to extend from La Boca all the way back home.