Last week's 5 biggest fantasy surprises: Vladimir Guerrero Jr. is slumping

Slumps are unavoidable in fantasy baseball. Even the best players in the game have a poor eight-game stretch at the plate.

The past week wasn't kind to some of the best hitters in the game. Washington Nationals superstar Juan Soto hit .200, with no home runs. Philadelphia Phillies slugger Bryce Harper posted a .154 batting average over his past 13 at-bats.

One of the biggest factors that separate elite players from average players is the ability to make quick adjustments. Elite players can fix their mechanics or approach quickly, ending their slump after a few games.

These are extremely small samples, and you already know Harper and Soto will rebound. But sometimes it's important to recognize even the best players have bad weeks — the question is, how soon will they rebound, if they do at all?

Ranks are based on standard Yahoo fantasy leagues

Vladimir Guerrero Jr., Toronto Blue Jays 1B

Fantasy rank over the last seven days: 775

Season-long fantasy rank: 155

You can lump Toronto Blue Jays slugger Vladimir Guerrero Jr. in with Harper and Soto. Guerrero has not been himself over the past week, hitting just .100 over his last 20 at-bats.

These things happen.

Guerrero had a stretch last April where he hit .136 over 7 games. In September, Guerrero hit .094 over an 8-game stretch. He still finished the year with a .311/.401/.601 slash line.

Dig deeper into Guerrero's numbers, and it's clear he hasn't been himself this season. There are still some positive trends — Guerrero's hard-hit rate, average exit velocity and max exit velocity remain strong. But his approach needs some tweaks if Guerrero hopes to repeat last season's numbers.

The biggest issue for him is his high 51.6 percent ground-ball rate. Guerrero should be used to this particular problem, as high ground-ball rates prevented him from reaching his ceiling his first two seasons in MLB. When you hit the ball as hard as Guerrero, you want to put the ball in the air, where you can do the most damage.

Guerrero made that adjustment last season, posting a career-high 36.5 percent fly-ball rate. The result: A career year and 48 home runs.

There is more evidence Guerrero isn't completely comfortable at the plate. His barrel rate is down from 15 percent to 9 percent, and he's not obliterating fastballs like he did last season, when he hit an incredible .374 against heaters.

The hard-hit numbers suggest Guerrero is healthy and has not lost any ability at the plate. He showed last season that he can elevate the ball, so fantasy managers should have faith he can correct his ground ball issues.

It's been a frustrating week or so, but Guerrero should get back on track. Whether he can repeat last season's dominance remains a big question, but 85 percent of that would still result in a tremendous fantasy season.

Wander Franco, Tampa Bay Rays 3B, SS

Fantasy rank over the last seven days: 581

Season-long fantasy rank: 118

One of the most hyped fantasy prospects in recent memory looked like a massive fantasy win in April. Tampa Bay Rays phenom Wander Franco hit .313, with 4 home runs, in the opening month of 2022. Those who took the plunge on Franco early looked like they got the steal of the draft.

May hasn't been as kind. Franco is hitting just .200 during the month. His last 10 games, in particular, have been awful. Franco has hit .057 over that stretch.

There's a pretty obvious reason for that, however. Franco injured his leg on May 10. His slide came immediately after that injury.

The situation puts Franco managers in a tough spot. The injury appears to be affecting his numbers, but the Rays are content to keep running Franco out there. Can fantasy managers deal with Franco's poor numbers until he gets over the injury?

At this point, the best situation would be a short stint on the Injured List. It's never good when fantasy managers have to replace an elite player, but some rest might be the best thing for Franco right now.

Franco managers might want to start looking at temporary replacements — more on that in a second — because the Rays can't afford to keep running this version of him out there.

Ranger Suárez, Philadelphia Phillies SP

Fantasy rank over the last seven days: 726

Season-long fantasy rank: 498

Ranger Suárez wasn't going to repeat last year's 1.36 ERA, but big things were expected after it looked like he took a leap forward in 2021.

He has yet to deliver a repeat performance.

Suárez's strikeout rate is down, his walk rate is up and his ERA sits just over 4.00. He hasn't been terrible, but his performance has been disappointing.

Some of this is regression. Suárez wasn't going to maintain a 0.34 home run per 9 rate, even with his excellent sinker. That pitch continues to be a strong weapon for Suárez. Hitters have a .317 slugging percentage against it in 2022.

Every other pitch, however, is getting hit hard. Batters are teeing off against Suárez's changeup, 4-seam fastball and slider. The slider isn't getting as much vertical break, but the other two offerings look similar, per Baseball Savant.

It could be an issue of lost pitch velocity. It's not a huge difference, but Suárez isn't throwing as hard in 2022. His sinker velocity sits at 92.6 mph after being at 93.2 mph last year. His slider velocity is down over 2 mph in 2022.

Suárez's sinker remains elite and that's good. But if Suárez is going to deliver on his hype, he's going to need to get his secondary pitches — especially his slider — back on track. If the slider velocity starts creeping up, that would be a positive sign.

Josh Rojas, Arizona Diamondbacks 2B, 3B, SS, OF

Fantasy rank over the last seven days: 14

Season-long fantasy rank: 505

True fantasy baseball sickos will remember last spring training when Josh Rojas was heading toward fantasy superstardom. Rojas did not deliver that, though he did hit a solid .264/.341/.411 last year. After a middling start to 2022, Rojas shot up the fantasy rankings last week.

Hitting three home runs in a single game will do that.

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Rojas has a few things going for him in fantasy. He can play virtually anywhere and he swipes bases. Is that enough to make him a must-add in leagues?

Rojas is doing some interesting things at the plate. He's clearly tried to tap into his power stroke. Rojas is pulling the ball and putting it in the air more often. His hard contact rate is up as well.

The most impressive aspect of Rojas' approach is his plate discipline. Rojas doesn't chase pitches out of the zone. When he does swing the bat, he's making more contact, both in and out of the zone. Both his strikeout rate and swinging-strike rate are down as a result, suggesting he can hit for a decent average.

Rojas is far from a sure thing. His average exit velocity is up, but Rojas doesn't hit the ball that hard. His max exit velocity is 103 mph this season, which ranks in the 35th percentile. That's going to cap his overall home run output.

There's enough here that Rojas is worth a pickup if you're struggling at second base or shortstop. And if you failed to snag an elite option at those positions — particularly second base — you're probably looking for some help at the moment.

Brady Singer, Kansas City Royals SP

Fantasy rank over the last seven days: 10

Season-long fantasy rank: 207

Kansas City Royals pitcher Brady Singer returned from Triple-A a new man.

Singer posted two straight scoreless starts last week, striking out 12 batters in 14 innings. Those performances should solidify Singer's spot in the Royals' rotation, but does it make him an intriguing fantasy option?

The most encouraging aspect of Singer's dominant stretch is that he's pounding the zone. Singer's walk rate sits at 5.3 percent, a promising sign. He's also seen a slight uptick in velocity, though that could be a result of Singer making three appearances out of the bullpen to start the year. Pitchers usually throw a few ticks higher out of the pen.

Everything else looks pretty standard for Singer. The sinker is inducing a lot of ground balls, but its whiff rate is way down. Singer's slider is hit or miss. Batters have a .294 batting average against the pitch, but it also has a 42.9 percent whiff rate. The changeup looks improved, but still might be a below-average pitch.

Due to Singer's bullpen usage, he has yet to throw 20 innings this season. His data could be a lot more unreliable compared to other players. With that said, it's probably best to take a wait-and-see approach here.

It's possible Singer has taken a step forward and can be a useful fantasy player, but there's nothing in his profile — yet — to suggest he's now a completely different guy on the mound.