Absolutely, I have seen a fringe player turn into a Pro Bowl star.
I'm not talking about a shockingly great rookie 3rd day pick or free agent. I'm talking about a player that has been in the league for a couple of year that barely hung on to a 53 man roster.
In these particular cases, nobody saw it coming. At some point it just clicked and they stared to ball out.
In fact, this is the story of the Cowboys 90s team, the left side of their legendary offensive line.
Both Nate Newton and Mark Tuinei were undrafted free agents.
Nate Newton's early career was all about dealing with his weight and the coach's insisting that he must reduce or face getting cut. He was seen as nothing more than a possible backup.
Then Jimmy Johnson came along. He could care less about the weight, he wanted monsters on the O-line. Jimmy realized Nate's athleticism. At 350 pounds, he could still dunk a basketball.
Mark Tuinei came into the league as a possible backup DT. In fact, he has a recorded NFL sack. In his 4th season, injuries forced Tom Landry to start him for 11 games. That was 1986.
However, once again, Jimmy came in 1989 and Tuinei was the starter that year. He started through 8 seasons, including 3 Super Bowls.
Both of these guys weren't instant phenoms. It's not like the whole league missed their talent. It was hard work and perseverance that eventually led them to NFL fame. They were just able to stick around for their first few years.
Towards the end of Witten's TE career, the Cowboys were desperately looking for a replacement. They drafted 3 TEs in th 2nd round and they didn't work out. They had a bunch of guys like Geoff Swaim, James Hanna, Blake Jarwin, and Rico Gathers. Nobody really liked Dalton Schultz.
I remember all the "cut him" posts on this forum. He wasn't exactly lighting the world on fire his first few seasons. He had 13 receptions his first two years.
In 2020 Schultz exploded to the point where the Cowboys couldn't afford him. He had over 80 receptions last season for the Texans.
It can happen. I'm not saying it will, but it could happen for Isaiah Land. Considering he is a LB, it couldn't come at a better time for the Cowboys.