Since the NFL Combine, Hue Jackson has been adamant in his belief in the age-old saying "one door closes, another one opens" when it pertained to Browns free agents.

Now that a handful of starters from last year's roster are employed elsewhere in the NFL, the time is now to prepare those players who could be tasked with filling some big cleats in 2016.

"I don't want to sit here and say, 'OK, well, we're going to give the season away,'" Jackson said at last month's NFL Combine. "What we have to do is go find players to fit in those particular positions so we have an opportunity to move forward. And we'll do that if it does go in that direction."

The Browns have added a handful of players to the roster via free agency, most notably quarterback Robert Griffin III last week. Many, many more pieces will be added in the draft, which kicks off exactly one month from today.

With offseason workouts just one week away, here are four players on the current roster who held roles for the Browns in 2015 and could very well be playing many more snaps in 2016.

OL Austin Pasztor

Though Pasztor never saw the field at tackle in 2015, he could be in line for a look this year in the wake of right tackle Mitchell Schwartz's departure. Pasztor is one of the Browns' more versatile linemen, and he proved as much near the end of last season when he started at left guard in the team's final four games. In his three seasons with the Jaguars, Pasztor, an undrafted free agent out of Virginia who played all over the line for the Cavaliers, started 20 games at right tackle. The opportunity is there for Pasztor, especially if the Browns don't address the position early in the draft. He'll compete with the likes of Alvin Bailey, a former Seahawk who signed with the Browns earlier this month, and Michael Bowie, who missed all of 2015 with a shoulder injury.

S Jordan Poyer

The first safety off the bench got plenty of work last year because of injuries to Tashaun Gipson and Donte Whitner. He ultimately started in four games -- three at free safety and one at strong safety -- and served as a productive fill-in, racking up 37 tackles and two interceptions. Gipson's departure to Jacksonville opens the door for Poyer, but the job won't be handed to him, as former Broncos and Texans safety Rahim Moore joined the squad as a free agent. Poyer has been one of the Browns' most valuable players on special teams and has stepped up when called upon. His fourth year in the NFL could call for even more responsibility.

LB Christian Kirksey

Kirksey's been a fixture on Cleveland's defense since the first week of his rookie season, but his third year in the NFL could include many more snaps now that Karlos Dansby is off the roster and Craig Robertson is with the Saints. Kirksey and Robertson often split the snaps down the middle at WILL while Dansby rarely, if ever, left the field at MIKE. Recently signed free agent Demario Davis appears to be a nice fit at MIKE, and Kirksey has the opportunity to lock down WILL all for himself. "He is going to be probably a starter for us," Browns defensive coordinator Ray Horton said in February. "We will continue to show them film of other players on other teams. 'This is what we want.' One of the things that we are going to try to impart with our players is 'This is how champions do it. This is how champions do it.' There is a way on the field and off the field to do things."

OL Cameron Erving

It's unclear where Erving will be slotted when the Browns go through their offseason workouts, but a big opening presented itself when Pro Bowl center Alex Mack left for Atlanta in free agency. Erving, of course, has experience at the position, but it was at the college level. Because Mack was healthy from start to finish in 2015, the opportunity never presented itself for Erving, who primarily worked at guard and left tackle throughout his rookie year. Lauded for his versatility, Erving was tasked with learning multiple positions and experienced some ups and downs when he saw the field at guard, a position he never played in college. Could a trip back to a comfort zone of sorts be the key to a big step forward in Year 2? Browns fans will get a clearer picture in the coming weeks.