This article is part of our IDP Analysis series.
Whether due to injury or a shift in the depth chart, we saw a number of young players emerge in Week 13. As we continue to barrel toward the fantasy playoffs, our focus will continue to split between potential playoff contributors and players who could become relevant in dynasty or keeper formats for the rest of the 2023 campaign and into 2024. With that in mind, let's look at some of the most notable risers and one faller from Week 13.
Risers
Mykal Walker, LB 
The Steelers are running through middle linebackers at a prolific rate, and Elandon Roberts (groin) was the latest to suffer an injury in Week 13. Walker had already progressed from the practice squad player to the active roster. On Sunday, he played in a season-high 97 percent of snaps. That led to 10 tackles, a result that was caused by Walker seeing more work against the run after working primarily in coverage for his first few weeks on the active roster. That's likely to continue with Cole Holcomb (knee) and Kwon Alexander (Achilles) sidelined for the rest of the season.
Desmond King, CB 
King has struggled to find a home this season, as he played sparingly for the Steelers before being released by the team in mid-October. A month later, he signed with the Texans' practice squad before being signed to the active roster ahead of Sunday's win over the Broncos. The path was completely cleared for him once Shaquill Griffin was
Whether due to injury or a shift in the depth chart, we saw a number of young players emerge in Week 13. As we continue to barrel toward the fantasy playoffs, our focus will continue to split between potential playoff contributors and players who could become relevant in dynasty or keeper formats for the rest of the 2023 campaign and into 2024. With that in mind, let's look at some of the most notable risers and one faller from Week 13.
Risers
Mykal Walker, LB
The Steelers are running through middle linebackers at a prolific rate, and Elandon Roberts (groin) was the latest to suffer an injury in Week 13. Walker had already progressed from the practice squad player to the active roster. On Sunday, he played in a season-high 97 percent of snaps. That led to 10 tackles, a result that was caused by Walker seeing more work against the run after working primarily in coverage for his first few weeks on the active roster. That's likely to continue with Cole Holcomb (knee) and Kwon Alexander (Achilles) sidelined for the rest of the season.
Desmond King, CB
King has struggled to find a home this season, as he played sparingly for the Steelers before being released by the team in mid-October. A month later, he signed with the Texans' practice squad before being signed to the active roster ahead of Sunday's win over the Broncos. The path was completely cleared for him once Shaquill Griffin was also waived prior to Sunday's game, allowing King to take over as the slot corner. He turned that chance into 10 tackles and appears to have found a new home in his second go-round in Houston.
Nephi Sewell, LB 
Sewell has played sparingly for the first year and a half of his career since entering the league as a free agent. However, he got his first significant chance in Week 13 due to the absence of Pete Werner (oblique) and came through with an eight-tackle performance. As soon as Werner returns, Sewell will almost certainly be sent back to an exclusively special teams role, so his intrigue for the rest of this season is limited. On the other hand, this could turn into an audition for a future role, as Zack Baun is the weakside linebacker opposite Werner. He's been uninspiring since being selected in the third round of the 2020 draft and is set to hit free agency this offseason.
Brown has taken over as San Francisco's starting strong safety in the absence of Talanoa Hufanga (knee). In two games since Hufanga has gone down, Brown has played 98 and 100 percent of snaps, racking up a total of 11 tackles. He doesn't have any peripheral stats to this point, but he's dropped into coverage 94 times combined between those two games (per PFF) and should have the chance for pass breakups and potentially picks moving forward.
Zach Sieler, DE 
Sieler got off to a hot start to the season, racking up four sacks in his first six games. He hit a lull in production from there, but after a 1.5 sack performance Sunday against the Commanders, he has 2.5 sacks across his last two contests. While his pass rush numbers have been inconsistent, Sieler has also logged the highest-tackle total of his career, which has helped smooth out the ebb and flow of his sack production. All told, he's having his best statistical season heading into the first year of a three-year, $30.8 million contract extension.
Mike Edwards, S 
Bryan Cook (ankle) suffered what appeared to be a significant ankle injury in Sunday night's loss to Green Bay, an unfortunate turn to his solid season. We hope the good news continues for him after an X-ray came back negative on Monday, but it would be a shock if Cook is able to retake the field quickly. The Chiefs also made it clear that Edwards would serve as direct replacement for Cook, as he saw his highest snap total of the season as well as his highest tackle total. Both of those trends should continue so long as Cook is out.
Fallers
Leonard makes his second appearance on the faller list this season, which is unfortunate because he had the chance to change the trajectory of his narrative depending on where he landed in free agency. While he likely wouldn't have stepped into a starting role among the Dallas linebacking corps – his other rumored landing spot -- the unit is much thinner there than his ultimate landing spot with Philadelphia. Now, he'll be forced to share playing time with Nicholas Morrow and likely Nakobe Dean (foot) at some point prior to the close of the year.
