Seltzer: The 6 X-factor players in Wednesday's packed slate of cup action

Andre Blake - Philadelphia Union - Close up

Six MLS clubs standing two games from cup glory will do battle in either the Lamar Hunt U.S. Open Cup or Canadian Championship action on Wednesday night, and each will be hoping for an X-factor performance to forge their path to victory.

We've taken the liberty of tabbing one player from each of the six cup chasers who can provide the crucial ingredient for success.

Brandon Vincent

Seltzer: The 6 X-factor players in Wednesday's packed slate of cup action -

Brandon Vincent | USA Today Sports Images

Chicago Fire strike ace Nemanja Nikolic has scored in each of the team's three Open Cup tilts, and continued production from him seems essential to hopes of claiming their first crown since 2006. But he is definitely a guy who relies on service to the box, and an injury to right back supplier Matt Polster has played a large part in Nikolic's shots-per-game average being sliced in half this season.

That leaves most of the deep crossing onus on left back Brandon Vincent, who just so happened to lead all MLS fullbacks in primary assists to a striker last season. Backline injuries have seen him pulled to the middle several times this term, which helps explain why both his crosses and key passes are down about 30 percent, and why he hasn't notched a helper since May 20.

Long story short: Wednesday would be a marvelous time for Vincent to make it his mission to get forward for as many targeted airdrops into the Philadelphia area as he can muster.

Andre Blake

It's no secret that goalkeepers suddenly accrue added value when knockout matches are on the docket. Extra time means intense pressure to keep a lid on goal, and spot kicks puts netminders in a glaring spotlight with the hardest work to do. As good as Andre Blake is, both penalty kicks and Open Cup tilts have often been quite unkind to him and the Philadelphia Union.

Let's review the numbers. Blake came up short both time he's been in an Open Cup shootout, including in the 2015 final. On those occasions, the Philly net star stopped but one of 12 on-target penalty tries. It's not a cup fluke; he's only stopped two of 15 spot kicks faced in league play.

The good news is Blake has emerged victorious from all three previous home meetings with the Fire. Could he ride that trend to finally shine in the Open Cup and get another crack at the championship match?

Chris Seitz

Seltzer: The 6 X-factor players in Wednesday's packed slate of cup action -

Chris Seitz | USA Today Sports Images

Believe it or not, the Houston Dynamo 'keeper is even more poised to play the X-factor role than Blake. Not only does LAFC coach Bob Bradley's infinity gauntlet house an array of gems, but Chris Seitz is one of those guys who often saves his best for the Open Cup.

Seitz has won eight straight cup decisions, a string that includes the 2016 final win for FC Dallas. For his career, he's 12-4 in Open Cup games with six shutouts. And while he's yet to be pressed into tournament shootout duty, the veteran is among the best penalty savers in MLS. Seitz has impressively turned away eight of 21 spot tries against since turning pro, with his latest stop denying Darwin Quintero a late equalizer in Houston's Round of 16 victory over Minnesota United in June.

Latif Blessing

Seltzer: The 6 X-factor players in Wednesday's packed slate of cup action -

Latif Blessing | USA Today Sports Images

When an opponent weighs up the threats posed by LAFC's best-in-the-West attack, it makes for an all-nighter study. Somewhere down a list stacked with big names, the opposition scouts come to Latif Blessing. The 21-year-old has steadily grown into a solid MLS winger, but he still falls in line behind the VelasDiomandes and Feilhabers when it comes to defensive gameplan priorities. 

When it comes to Open Cup play, that sort of inattention can prove fatal. Yep, Blessing is a licensed USOC killer, having chalked up five goals and a couple of helpers in nine career cup outings. During Sporting KC's title run from last year, he hit the extra-time winner against quarterfinal foes Dallas and bagged their opener in the 2-1 final win over the New York Red Bulls. In other words, Houston would do very well not to lose track of the visitors' sly No. 7 shirt on Wednesday night.

Jonathan Osorio

Seltzer: The 6 X-factor players in Wednesday's packed slate of cup action -

Jonathan Osorio | USA Today Sports Images

Considering the fact that the Toronto FC midfielder has been the Canadian Championship holders' most consistent performer in MLS play this season, and the fact that he routinely finds nets during cup play, it should come as no surprise to find Jonathan Osorio's name here.

Osorio has eight goals in 24 career cup contests, with four of those strikes coming in his 16 Canadian Championship games to date. He scored in both legs against semifinal victims Ottawa. Even when he's not lighting the lamp, the Toronto native finds ways to help the Reds win.

Against Vancouver, Osorio can also be instrumental in slowing down counterattack speedsters Alphonso Davies and Yordy Reyna. Both will pass near the TFC midfielder's jurisdiction, so his ability to shade over to offer help for Auro and Michael Bradley will be as key as his blooming offensive game.

Russell Teibert

Seltzer: The 6 X-factor players in Wednesday's packed slate of cup action -

Russell Teibert | USA Today Sports Images

They may be underdogs, but one could still easily name a small of handful of players Vancouver should rely heavily upon against Canadian Championship final foes TFC. But if they are to defeat the defending champs, the Whitecaps will need someone like midfielder Russell Teibert to play the unsung hero.

The 25-year-old will be up for his 22nd Canadian Championship match on Wednesday. He's already played a part in four white-knuckle finals, but has celebrated the crown just once. Throw in a harsh 3-2-7 record when Teibert faces TFC, and he will have every motivation to help the Whitecaps pull a surprise in this year's title tie.

How can he do that? Well, his primary job will be block lanes to Zone 14, starving service to the creative likes of Jozy Altidore and Victor Vazquez in that danger area. And when his interference causes turnovers, Teibert can safely spring the Caps' lethal break.