The Senate's top Republican and Democrat were split on Sunday over the possibility of Judge Neil Gorsuch being confirmed to the Supreme Court ahead of a scheduled Senate vote this week.

Senate Majority Leader Mitch McConnell, R-Ky., vowed on "Fox News Sunday" that "we’re going to get Judge Gorsuch confirmed this week."

Gorsuch, President Trump’s pick to fill the high court seat of conservative Associate Justice Antonin Scalia, will almost certainly have enough votes to pass the GOP-controlled Senate Judiciary Committee Monday, but will struggle to get 60 votes for final confirmation by Friday.

Should Democrats attempt a filibuster, McConnell was expected to seek a change in Senate rules allowing a simple majority to confirm the nomination.

On Sunday, McConnell did not tip his hand over whether he would use the so-called "nuclear option," telling "Fox News Sunday," "We’ll know through the course of the week ... It’s in the hands of Democrats."

Senate Minority Leader Chuck Schumer, D-N.Y., predicted on NBC's "Meet the Press" that Gorsuch would not pass the 60-vote benchmark and argued that Trump should huddle with Democrats and Republicans to "try to come up with a mainstream nominee."

"Look, when a nominee doesn't get 60 votes, you shouldn't change the rules, you should change the nominee," said Schumer.

Later Sunday, two Democratic senators split over whether to support Gorsuch. Joe Donnelly of Indiana said he would vote in favor of Gorsuch's confirmation while Sen. Jon Tester of Montana announced he would not back the federal appeals court judge based in Denver.

Donnelly became the third Democrat to break with the party as Republicans line up behind President Donald Trump's choice for the high court.

With 52 Republican senators, eight votes from Democrats or the Senate's two independents would be needed to advance the nomination and prevent a filibuster. So far, only Donnelly of Indiana, Heidi Heitkamp of North Dakota and Joe Manchin of West Virginia — all representing states Trump won in November and all up for re-election next year — have said they will vote to confirm Gorsuch.

Tester represents a state won by Trump and faces re-election, too, but he said Gorsuch did not directly answer questions when the two met or during the confirmation hearing. Tester said he based his decision on the judge's past cases, noting that he found troubling Gorsuch's record on privacy and that he believes Gorsuch places corporations over people.

Donnelly called Gorsuch, 49, "a qualified jurist who will base his decisions on his understanding of the law and is well-respected among his peers."

The Associated Press contributed to this report.