Entering Week 7 of the MLB season, fantasy baseball players are looking for difference makers off of the waiver wire. A strong Week 7 fantasy baseball pick up could be the difference between making the playoffs or not.

It's hard to find true stars on the waiver wire. Guys like Aaron Judge and Shohei Ohtani were obviously drafted. Other players who have broken out this season have likely already been claimed. However, there doesn't mean there isn't still value out there.

The waiver wire allows players to make major additions to their roster after the draft. Week 7's waiver wire will be no different. All four players are poised for a major opportunity with their team. That bodes well for their fantasy baseball potential.

Any of these players have an opportunity to turn around any roster. They make up our Week 7 top four fantasy baseball waiver wire pick ups.

Matt Mervis – 1B Chicago Cubs 

Before his call up, first baseman Matt Mervis was ranked as the sixth-best prospect in the Chicago Cubs system, via MLB Pipeline. Now that he is in the majors, Mervis is ready to prove he belongs.

The first baseman earned his call up after a scorching start at the AAA level. Through 24 games, Mervis was hitting .286 with six home runs and 17 RBI. Throughout his entire 234 game minor league career, Mervis hit .276 with 51 home runs and 190 RBI.

Mervis has already gotten into two games for the Cubs since his call up. He is hitting .250 with two RBI through his first eight plate appearances.

The first baseman will need to cut down on the strikeouts – he already has five. However, Chicago is clearly high on him. After they called him up, expect the Cubs to utilize Mervis frequently at first base. Opportunity equals success in fantasy baseball

Bryce Miller – SP Seattle Mariners 

Bryce Miller had a historic MLB debut for the Seattle Mariners. With Miller expected to stay with the Mariners long-term, the Seattle top prospect has a chance to become a star.

Miller dominated the Oakland Athletics in his debut, pitching six innings of one-run baseball. The right-hander struck out 10 and walked none, becoming just third pitcher in MLB history to accomplish that feat in their debut.

The Mariners know just how good Miller can be. Before his call up, he ranked as the second-best prospect in Seattle's organization and the 88th-best prospect in all of baseball, via MLB Pipeline. Over his 36 minor league appearances, Miller pitched to a 7-6 record with a 3.65 ERA and a 196/51 K/BB ratio.

While his impressive debut came against the lowly A's, Miller proved he can succeed at the MLB level. With the RHP staying in Seattle's rotation, Miller offers major long-term fantasy baseball upside.

Logan Allen – SP Cleveland Guardians 

Logan Allen is another top prospect getting an opportunity with his major league team. Thus far, Allen has shown that he deserves to stay with the Cleveland Guardians.

Allen has made three starts since his big league call up. He holds a 1-1 record with a 2.70 ERA and a 19/5 K/BB ratio. Through all three of his starts, the left-hander hasn't allowed more than two earned runs. In his first two starts, Allen struck out eight batters apiece.

He entered the season ranked as the eighth-best prospect in the Guardians system, via MLB Pipeline. Over his 51 minor league appearances, Allen held a 18-7 record with a 3.48 ERA and a 340/82 K/BB ratio.

Allen has a propensity to miss bats, without allowing many walks in the process. He has been impressive during his stay with the Guardians. Cleveland has no reason to send him back down amidst his hot streak. Fantasy baseball players should look to grab Allen before another strong start blows up his ownership.

Esteury Ruiz – OF Oakland Athletics

The Oakland Athletics are tied with the Kansas City Royals for the worst record in the MLB at 8-26. With talks of the team moving to Las Vegas, there hasn't been much hype around the A's. However, Esteury Ruiz is providing a major spark to both the Athletics and fantasy baseball players.

Oakland acquired Ruiz in the trade that sent Sean Murphy to the Atlanta Braves. Over his first 34 games with the A's, Ruiz has looked like a smart addition and a possible roster cornerstone.

Ruiz is hitting .273 with 16 RBI and 16 runs scored thus far. However, it's his 16 stolen bases that make Ruiz a prime Week 7 waiver wire pickup. Ruiz is currently leading the MLB in stolen bases.

Both fans and fantasy baseball players haven't been paying much attention to the A's. But Ruiz has suddenly found himself atop the stolen base leaderboard. As long as he is hitting and swiping bags, Ruiz will be in Oakland's lineup.

A fantasy baseball owner in desperate need of stolen bases should look no further than Ruiz.