On the final weekend before the start of the 2018 regular season, the Buccaneers trimmed their roster to 53 players, in the process keeping six cornerbacks. The team had a good idea of how it would arrange its starters, including the slot corner, and there was some notable depth to help get through a long season.

By the time the Buccaneers actually got to their first game, they had seen starter Brent Grimes suffer a practice-field groin injury and reserve De'Vante Harris hit injured reserve with a hamstring ailment. And by the time the Buccaneers finished that first game, they had lost starter Vernon Hargreaves to what would prove to be a season-ending shoulder injury.

So, plans change, and sometimes at breakneck speed.

"Once the season starts and sometimes even before the season starts, injuries are just a very unfortunate part," said Head Coach Dirk Koetter. "Vern had really done a nice job all through training camp, all through the preseason and he made a beautiful play on the play he got injured on. Just look in our own division, look at the guys that are hurt. I feel horrible for Vern because he didn't do anything to deserve this, but that's NFL football right now. That's the world that we live in. Every team's going to have them every week and it just means the next guy's got to come up and be ready to go."

Indeed, the Atlanta Falcons have already lost defensive starters Deion Jones and Keanu Neal to injured reserve, and Neal is definitely done for the year. The Panthers saw their starting right tackle, Daryl Williams, suffer a season-ending knee injury in Week One and also lost tight end Greg Olsen for an undetermined time to another foot fracture.

For the Buccaneers, the question marks are obviously at cornerback, and the answers are probably going to be multiple and layered. And they're going to involve, by necessity, some big contributions from second-round rookies M.J. Stewart and Carlton Davis.

From the looks of how the team started the game against the Saints, they likely intended to play Grimes and Hargreaves on the outside, then move Hargreaves into the slot and play Davis on the outside in nickel packages. Now, at least two of those three roles will need to be rethought, and all three if Grimes is still unavailable in Week Two. He did not practice on Wednesday as the team began preparing for the Philadelphia Eagles' visit on Sunday.

The Buccaneers also promoted third-year corner Javien Elliott from the practice squad after Harris went to injured reserve and brought in veteran Marcus Williams on Tuesday after the loss of Hargreaves. Both will almost certainly be needed at some point, even if they don't play extensively right away.

"In this case, we had to make a couple roster moves and we'll be getting Brent Grimes back soon," said Koetter. "And the rookies, they'll be playing a bigger role."

The Bucs played Davis for 56 snaps on Sunday but also spelled him a couple times with Stewart, who got 19 snaps in a couple different roles, including in the slot. The coaches planned before the game to take Davis out a couple times to allow him to catch his breath and keep his head from swimming in his first real NFL game. That game happened to be against one of the most prolific and precise passers of all time, and while the Saints' passing numbers were gaudy, Defensive Coordinator thought the two rookies handled the situation well, all things considered.

"Those young guys that we drafted last year in April we knew that they were going to have to come in and contribute," said Smith. "I didn't think it would be Week One and Week Two, but they're guys that have a good understanding of what needs to be done in the secondary. They've not really had the type of work that we'd like. They've all missed time in the preseason. We've had to improvise and adjust, but that's part of it. They'll remember their first NFL game playing against a Hall of Fame quarterback like Drew Brees. They found out in the NFL it's never over until it's really over."

The other major piece to the new cornerback puzzle is third-year player Ryan Smith, who stepped in for Grimes on Sunday. Smith spent his rookie year learning the safety position, then was switched back to cornerback last year and ended up playing extensively due to another rash of injuries at the position. He is ready to step up again.

"I think [it's] just confidence," said Koetter of Smith. "Ryan's always been a good tackler, he's always had good speed, but there's a confidence factor to playing any position. When you go against the quarterbacks that you go against in our division and against this league…I think the young rookies went through a little bit of that on Sunday when they saw that guy's going to put the ball on the money almost every time. It's just something that you've got to get used to in this league and those guys will all tell you you've got to have a short memory."

Still, however you arrange it, the Buccaneers are going to need a much larger contribution from their two rookies early in the season than seemed likely only a week ago. Stewart and Davis have already learned that familiar "next man up" mantra, but it was admittedly surprising to see that man in front of them be lost for the season almost before it began.

"It's crazy to see how quickly that can happen," said Stewart. "It's a dose of reality."

Stewart is an obvious candidate to take over Hargreaves' job in the slot, though Elliott also has experience there. His first game was another sort of dose of reality but he thinks it was the perfect way to get his career kick-started.

"If I had to picture it any way, it would be that way," he said. "That's a great game to start off with, going against a Hall-of-Fame quarterback in Drew Brees, a good receiver in Michael Thomas and a great running back in Alvin Kamara. That's a great tandem right there that I'm going against in my first NFL game. That was just an eye-opener – this is what the NFL is all about so now it's time to ball."

Both Stewart and Davis missed time during training camp due to minor injuries, as Smith noted. However, when they were in the mix they often impressed, building confidence that they could be ready to contribute quickly. While Stewart is seen as a slot guy who could also help on the outside, Davis is a taller corner who could match up well on the outside against bigger receivers.

Neither has the experience of Grimes or even Hargreaves, but they have to start somewhere. That start just happens to be a bit sooner than expected.

"It doesn't matter who's out there, you have to do your job," said Davis. "Obviously Brent and Vernon are key pieces to our secondary but what are we going to do about that? You have to have that next-man mentality and be ready to go. We kind of have to expect that going into the season – guys get hurt all the time. So you've got to have that in the back of your mind. That being said, we prepare every week like we're going to start, so it's not much of a difference."