Last season, when he was brand new to college football, Xavier McKinney would spend extra hours watching film with the coaches and practice alone by using cones to perfect his steps. Little did he know the time invested then would prove so valuable now.

But it has, because the sophomore safety and former four-star recruit is a key figure in secondary that has been completely overhauled.

Throughout fall camp, he has been a fixture on the field as Alabama coach Nick Saban has experimented with McKinney's teammates at various defensive back positions. Patrick Surtain II, Shyheim Carter and Trevon Diggs are among those who have been moved around within the back end. But McKinney has remained firmly planted at free safety -- the spot manned by junior Ronnie Harrison last season.

Had Harrison not elected to forgo his remaining year of eligibility, he would have been the undisputed face of the secondary.

Now, McKinney is a leader of the unit by default, coincidentally wearing the same No. 15 once stitched to the front and back of Harrison's old Alabama jerseys.

"I know my coaches have some plan for me," the 6-foot-1, 198-pound McKinney said. "All I am doing is trusting the process and just giving my all each and every play for practice and trying to get better for my teammates and my team so that we can focus on being a better team."

As a freshman in 2017, McKinney played 94 snaps and appeared in 13 of Alabama's 14 games. The experience he gained is relatively meager considering the weighty role he is assuming this season. But McKinney has received positive reviews throughout the preseason.

Last week, Saban cited McKinney as one of the two defensive backs who has "played with the most consistency."

That's not surprising considering McKinney's mild demeanor. Unlike the mercurial Harrison, McKinney appears to approach his job in a clinical fashion.

He did so last year as he worked to master Saban's coverage schemes that have rules based on routes and formations.

"It's complicated," McKinney said. "It can be complicated when you first get here. But if you study the plays enough and do enough overtime you'll get the plays down. I got it now. It was a work in progress a lot last year, though. It took me a little while to get it down pat, and I have been working on it a lot more. But I've got it."

His teammates notice.

"He's a guy that can make the calls across the board," said safety Deionte Thompson.

And in turn, he's become an indispensable part of a program he entered not too long ago.

Rainer Sabin is an Alabama beat writer for the Alabama Media Group. Follow him on Twitter @RainerSabin