There is a growing consensus from Pentagon watchers and people inside the building that acting secretary of defense Pat Shanahan is potentially days away from being officially named as the nominee for secretary of defense by President Donald Trump.

It’s not the first time there has been a round of rumors that a nomination is about to emerge, but this time does feel different. There is a growing confidence among staffers about the nomination, particularly after the surprise announcement that Secretary of the Air Force Heather Wilson would be leaving the Pentagon come May. She herself was seen as a potential SecDef nominee, and someone who has internally clashed with Shanahan in the past.

Serving to solidify the consensus that this nomination is Shanahan’s to lose is the lack of other suitors — Secretary of the Army Mark Esper has been seen as a contender but does not seem to have gained traction in Congress, and the White House reportedly offered the gig to several nominees earlier this year, all of which turned it down.

And then there are the comments from the White House.

“The president has a great deal of respect for acting Defense Secretary Shanahan. He likes him, and when the president is ready to make an announcement on that front, he certainly will," said White House press secretary Sarah Huckabee Sanders on Monday.

Now, Shanahan faces two potential issues as he nears the finish line. The first he can’t control, the second he can.

The first issue is the ongoing situation with the Boeing 737 Max program, with commercial jets grounded all over the world following the fatal crash of an Ethiopian airliner. That design underwent significant development while Shanahan was in charge of production activities for the commercial airplane families, and he often talks about bringing his commercial best-practices and lessons-learned from Boeing into the Pentagon.

But according to those who followed Shanahan’s work at Boeing, he had little if anything to do with the 737 Max program; his work was focused on larger planes, such as the 787 and 747 programs. But given Trump’s recent comments about the plane, it’s not inconceivable that the situation could become a black mark against Shanahan in the commander in chief’s sometimes quick-changing estimation.

The second, and much bigger, risk comes from his testimony Thursday in front of the Senate Armed Services Committee. Technically, his appearance is a routine budget posture hearing. But given the swirl of rumors about his future, it has taken on more of a feeling of a pre-nomination hearing.

In essence, the hearing represents something of a final test: get a passing grade from members of the committee, as well as the president, and the job appears to be his. Stumble into a trap laid by one of the many presidential candidates on the committee, turn off key senators, or appear to put too much distance between himself and the president, and Shanahan may stumble at the finish line.

Certainly, those close to him are aware of the stakes, with one administration official familiar with Shanahan’s thinking noting that “he’s not a politician, he’s an engineer. This is his second hearing, ever, whereas [former Secretary of Defense Jim Mattis] had decades of hearings. So that was a different experience. He has a good working relationship with Congress — just the facts, not here to play games.”

As a result, expect Shanahan to try to thread the line between traditional defense situations and statements from the president. Expect him to emphasize the importance of alliances, while noting that NATO needs to continue to increase spending. His concerns about China, about whom he feels passionately is the greatest threat to America’s security long-term, will likely be his fallback should a question get too far from his comfort zone.

The biggest challenge will likely be navigating the transgender issue and the decision to use DoD appropriations to fund the border wall, although doing so will likely be impossible. In those situations, Shanahan will have to follow the line so as to not cross either Trump nor Senate Armed Services Committee Chairman Jim Inhofe, who has expressed support for both moves while offering at-times tepid support for Shanahan.

Still, barring a major blow-up or embarrassment at the SASC hearing — and again, with Trump, nothing can be ruled out — those close to Shanahan strongly believe the nomination is coming. Expect all eyes on the would-be-secretary when the hearing kicks off.