A surging Sen. Elizabeth Warren will have her first chance to confront primary frontrunner Joe Biden on the debate stage Thursday night, as the top 10 Democrats running for president square off in Houston at a critical moment in the race.

The former vice president has maintained his status atop the primary polls, but Warren, D-Mass., has seen her numbers -- and crowd sizes -- grow in recent weeks. They have not appeared together on the same debate stage until now.

The other top-tier Democratic contender, Sen. Bernie Sanders of Vermont, who like Warren represents the progressive and populist wing of the party, will also be in Houston.

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But much of the buzz heading into Thursday night has focused on the two hopefuls standing center stage: Biden and Warren.

Two big questions heading into the debate: Will the two candidates, who come from very different wings of the Democratic Party, take aim at each other during the nationally televised prime-time showdown? And can Warren, who until now has not faced much direct criticism from top-tier candidates during debates, take the heat?

Biden campaign officials previewed some fireworks, arguing ahead of the debate that the field needs more than just plans: "We need action."

It was an implicit swipe at Warren, who famously has developed detailed action plans for a wide range of issues.

Warren and Biden have taken subtle jabs at each other in recent weeks.

“There is a lot at stake and people are scared,” Warren emphasized last weekend, in an address at the New Hampshire Democratic Party’s annual convention, as she noted the urgency of defeating President Trump in the 2020 election.

In what appeared to be a shot at Biden -- who has made electability a key part of his White House bid – Warren said “we can’t choose a candidate we don’t believe in because we’re scared.”

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Last week Biden appeared to take aim at Warren during a high-profile climate change forum televised on national cable TV, saying “plans are great, but executing on those plans is a very different thing.”

Warren has released one progressive policy proposal after another during her presidential campaign and is known for saying, “I have a plan for that.”

Asked about Biden’s comment, Warren told reporters: “I think we start with a plan and then we get out there and fight for it. To me that’s what being president is all about.”

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Due to the luck of the draw, Biden and Warren have not yet appeared on the same stage during the first two rounds of debates. For each of the first two rounds, the field of some 20 candidates was split in half for debate events over two consecutive nights.

But with the field shrinking and criteria toughening, all 10 candidates who made the cut for this matchup will share a stage for a single-night debate Thursday, hosted by ABC.

Warren has so far refrained from painting contrasts with her top rivals for the nomination. She told Fox News on Saturday that "I'm not here to criticize any other Democrat or anyone else's campaign. I'm here to talk about what I'm running for as president."

Biden's camp has signaled that he's unlikely to lead the charge against Warren.

“Let's be clear, there will be 10 candidates on the debate stage, not two. And regardless of who is or isn't attacking Joe Biden, Biden is focused on running his race,” a senior Biden adviser told Fox News this week.

Democratic strategists agree. Veteran Democratic strategist Zac Petkanas predicted that “they are very likely to leave each other alone.”

Petkanas, who served as the Hillary Clinton campaign’s director of rapid response in the 2016 race, noted that while some in the Biden camp are sending signals that the former vice president may paint contrasts with Warren, “I doubt very much that the candidates themselves are going to get into a scrape.”

“Elizabeth Warren has done extremely well by staying above the fray,” he added. “She is the little engine that continues to climb and build a strong foundation of support that is going to help her win the nomination.”

But strategic communications consultant Ben LaBolt, who served as national press secretary for President Barack Obama’s 2012 reelection campaign, isn’t ruling out some friction between Biden and Warren.

“I think she signaled she's willing to take the fight not only to Trump but to compete as hard as she needs to win the primary," he noted. “Inevitably, campaigns are about laying out choices. Democrats should not go below the belt in attacking each other or damaging potential nominees irrevocably, but I do expect some level of contrast between the candidates in this debate.”

Biden has faced incoming fire from his rivals on the debate stage the past two rounds, and Thursday night’s showdown should be no different.

“I think there is going to be pile-on on Joe Biden and that makes a lot of sense,” Petkanas said. “A lot of the other campaigns believe that his support is soft and is moveable.”

Biden was coldcocked by Sen. Kamala Harris of California in the first round in late June and he weathered repeated jabs from Sen. Cory Booker of New Jersey and Sen. Kirsten Gillibrand of New York – who dropped out of the race last month – in late July’s second round.

“The reality is Joe Biden needs to come down in support if we’re going to see other candidates increase their support,” Petkanas noted.

LaBolt empathized that the other candidates on Thursday’s debate stage have a choice to make. “Will they focus solely on laying out the case or will they take the contrast not only to Trump but to those candidates eating up the largest portion of their potential vote share?” he said.

Warren remained unscathed in the first round of debates, but she and Sanders faced attacks by more centrist lower-tier candidates over their progressive proposals – specifically the "Medicare-for-all" proposal -- during the second round.

With no let-up in Warren’s rise – she’s now all tied up with Sanders for second place behind Biden in nearly every recent poll – expect her, along with Sanders, to face more criticism.

LaBolt said that “while Biden has been a focus of attacks, other candidates may have a better shot peeling off support from Warren or Sanders. How they engage with others on the stage will be the most interesting chess match of the evening.”

Fox News' Peter Doocy and Brooke Singman contributed to this report.