You never know which player will become valuable through the fantasy baseball waiver wire. A change of scenery, opportunity or overall plans can take a player from an afterthought to a key contributor.

It's hard to find those kinds of players on draft day. While predictions are one thing, fantasy baseball owners won't know how a team functions and operates until games are played. With injuries and overall roster changes coming daily in MLB, new players every week become waiver wire diamonds.

Scurrying through the rough to find those gems takes any fantasy baseball team from good to great. While the draft will set the skeleton of your team, the waiver wire ensures you can add players on hot streaks or bound for a greater role on their respective teams.

The Week 9 waiver wire reflects that perfectly. Some players are filling in due to injuries. Others have shined when least expected of them. All of them make for strong additions to your fantasy baseball roster entering Week 9.

Every player on this list is owned in 20 percent or few of all ESPN fantasy baseball leagues.

Edmundo Sosa, SS, Philadelphia Phillies 

Philadelphia Phillies shortstop Edmundo Sosa (33) reacts after scoring on a bases loaded walk during the fifth inning against the New York Mets at Citizens Bank Park.
Bill Streicher-USA TODAY Sports

Trea Turner is making rapid progress in his return from his hamstring injury. However, as long as he is out, Sosa has taken over his role at shortstop. As long as Sosa is getting that opportunity, he is a solid waiver wire addition.

Over his 21 games in 2024, Sosa is hitting .296 with a 13 runs scored, a home run, eight RBI and two stolen bases. His numbers may not jump off the page, but Sosa is hitting .333 with five runs scored, three RBI and a stolen base over his last six games.

Sosa's value is boosted tremendously by Turner's absence. Perhaps Philly finds a way to keep Sosa in the lineup upon Turner's return, but there is no guarantee of daily playing time. Still, Sosa is making the most of his newfound opportunity.

As long as Sosa is hitting and in the lineup, fantasy baseball owners should keep their eye on him. It may not be long-term value, but his everyday at-bats in the short-team will be beneficial.

Shea Langeliers, C, Oakland Athletics 

Catcher is one of the weakest positions in fantasy baseball. Makes sense that the backstop from one of MLB's worst teams actually makes for a intriguing waiver wire addition.

While the Athletics are just 19-29, Shea Langeliers is a former top prospect. He ranked as the second-best in Oakland's organization in 2022, via MLB Pipeline. Even if the Athletics are focused more on their move to Las Vegas than winning, developing Langeliers into their catcher of the present and future should be a top priority in Oakland.

So far, the backstop has shown that he has the skills to live up to that hype. Over 42 games, Langeliers is hitting .223 with 10 home runs and 26 RBI. His batting average has looked better, as Langeliers is hitting .324 over his last 10 games. If he can remain more consistent at the plate, while provided premium power, the Athletics catcher could file that hole on your roster for the remainder of the season.

The Athletics are not a good team. But when he's in the lineup, Langeliers is often hitting cleanup. In that position, and in such a weak spot in catcher, Langeliers gives fantasy baseball managers an intriguing option off of waiver wire.

Kevin Pillar, OF, Los Angeles Angels 

Los Angeles Angels center fielder Kevin Pillar (12) runs to first after hitting a RBI single in the seventh inning against the St. Louis Cardinals at Angel Stadium.
Kirby Lee-USA TODAY Sports

At 35-years-old, going from the wilting Chicago White Sox to the beaten down Los Angeles Angels, no one expected a career renaissance from outfielder Kevin Pillar. While his sample size is still small, Pillar has proven them all wrong.

Over his 11 games since joining the Angels, Pillar is hitting .432 with three home runs, 14 RBI and four stolen bases. When he has been in the lineup, Pillar predominantly bats fourth or fifth. Much like the situation with Langeliers, that's an opportunity that can't be ignored.

But unlike Langeliers, Pillar is a veteran of the sport. He isn't expected to shape the Angels' outfield foundation for years to come. Still, with Mike Trout injured, LA needs somebody out there. So far, Pillar has gone above and beyond expectations.

It's important to note that Pillar hit just .160 over his 17 games with the White Sox. His hot streak could run cold at any moment. But until it does, Pillar has shockingly become a player to add off of the Week 9 waiver wire.

Jalen Beeks, RP, Colorado Rockies

When it comes to relief pitchers in fantasy baseball, saves are key. If a player is guaranteed the ninth inning role, they are more likely to be worth owning. While it may be the Colorado Rockies, Jalen Beeks appears to be the latest reliever to get promoted to ninth inning duties.

Beeks has recorded four saves on the season, with three of them coming over his last four games. While Colorado had tried players like Justin Lawrence and Tyler Kinley in the ninth, they hold 4.42 and 8.27 ERAs respectively. Manager Bud Black has now consistently gone to Beeks in save opportunities.

Beeks, in turn, has put up a 2.21 ERA over his 18 appearances. His 14/11 K/BB ratio is concerning, but Beeks has been one of the best relievers in Colorado throughout the 2024 campaign. Now, he has been given an opportunity to command the ninth inning.

At 15-30, those save opportunities might not come as often as closer on top flight teams. However, it's rare to find closers freely available on the waiver wire. If in need of saves, Beeks is your best bet at taking over the category heading into Week 9.