A great TV drama, like a great football team, is often defined by depth. You need stars to succeed, but you also need players further down the roster who can perform when their number gets called.

Alan Sepinwall of the Newark Star-Ledger has heaped praise on Friday Night Lights from the get-go, with most reserved for the fantastic performances by Kyle Chandler as Eric Taylor and Connie Britton as his wife, Tami.

But one of the best pleasures of Friday Night Lights is its great top-to-bottom cast. In particular, two actors who began the season chained to the end of the bench - Adrianne Palicki as the outcast sexpot, Tyra, and Jesse Plemons as an outcast geek, Landry - were playing like MVPs by the finale.

When the series began, Tyra and Landry existed, at best, as appendages to more important characters - Tyra as the girlfriend of alcoholic fullback Tim Riggins, Landry as the sidekick of shy quarterback Matt Saracen.

"Early on, (producers) Jason Katims and Peter Berg both told me they had no idea what they were going to do with my character," Adrianne Palicki said.

"With Tyra, we didn't really know a lot about her," Katims admits.

So he and the other writers started filling in the blanks.

In the 12th episode, "What to Do While You're Waiting," they introduced Tyra's mom, an arrested development case with an addiction to abusive boyfriends, one of whom Tyra chased out of the house.

It was probably too much back story to dump into a single episode, but it marked a turning point for the character. Soon Tyra Collette befriended Julie Taylor, became a pet project of Mrs. Taylor, and became a key part of the series.

"When you introduce her mother, her sister, her mom's problem with men, suddenly you understand her," says Katims."When you see her have this connection with Tami and this friendship with Julie, you have this fully dimensional character, and Adrianne Palicki just took it and ran with it and blew us all away. She's become one of my favorite characters."

Landry, meanwhile, would hover on the fringes of the series, cracking jokes in Matt Saracen scenes but remaining so inconsequential that even Coach Taylor began referring to him as "that Lance kid."

Outside of an ironic contrast between his first name (probably a homage to legendary Dallas Cowboys coach Tom Landry) and his lack of interest in athletics, there were few hints about who he was.

"It was interesting having a role who was always there but no one knew that much about him," says Jesse Plemons. "It was a process."

Part of that process was in the realization that Jesse Plemons is funny, an invaluable commodity on a show filled with so much angst elsewhere.

In one early episode, Landry dragged Saracen to a thrift store to outfit him for a date with the coach's daughter, selling himself as a romance expert.

Matt Saracen pointed out that Landry's last girlfriend was in the fifth grade, and Landry went off on a rant (improvised by Jesse Plemons) about how painful that break-up still is.

"Everybody wants to write scenes for Landry because he's charming, and you can give him the phone book and he'd make it funny," says Katims. "(Jesse Plemons) just gets the humor and plays with such commitment to this kid. Even though he's the funny sidekick, he plays it so real, so not over-the-top, and that's what makes it funny."

Landry Clarke's interest in Tyra began as another joke - watch the dork whose big extracurricular activity is a Christian speed metal band (Crucifictorius) make a fool of himself chasing after the blonde bombshell - but that changed as Tyra fought off a rapist while waiting for a tutoring session with Landry.

"As soon as I heard about (the romance storyline), I thought, 'Ah, I don't know about that. That's a little far-fetched, Landry and Tyra? I don't think so,'" says Plemons.

"But I think the only way for that to have worked was how they wrote it, for something huge to have happened. Like I said, when it comes down to it, they're both kind of outcasts, just in a different way. People don't look at her as smart or going places, they just don't, and people don't look at Landry; they look at him like he's nuts, pretty much. There's a kind of common ground between the two of them, they just both get each other."

In a later episode, Landry fears Tyra is getting back together with Tim Riggins and verbally tears her to shreds, asking whether, like her mom, Tyra wants to "spend the rest of your life with someone who cheats on you, who drinks all the time, who's going to end up working at a gas station and, you know, puking up his paycheck."

"Jesse had me in tears, he was so intense," says Adrianne Palicki. "He's a phenomenal actor. I'm really lucky."

The season finale put the two of them together for a road trip that Landry built up in his mind as a romantic getaway, while Tyra assumed it was carpooling.

In a scene at the end - cut away from the season finale at the last minute - Tyra realized her friend's true intentions and gave him a platonic peck on the cheek, one that he immediately misinterpreted as something else.

"We decided this was something for next year," says Katims. "And we are following up on it in a major way. The first arc, the Tyra-Landry connection, which we all love, is something we're going to play to the hilt."

Tyra's attacker is going to return, and, according to Katims, something will happen that will "tie their lives together in a way that's more intimate than they ever would have imagined."

"Part of me wants Tyra to end up with Landry," says Palicki, "because he's such a great guy, even though I know that they're in that place in high school. It might take her a while to get to that point, but I want her to be with someone awesome."

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.