With the minor-league season coming to an end within the next week, this will be the final Prospect Watch of the year.  Last edition we highlighted five of the best surprises of the season; this week, as promised, we're focusing on the disappointments. To be clear, we're not saying these players are bad -- just that they underwhelmed relative to expectations on them.

Let's get to it then.

Royce Lewis, SS, Twins

Lewis, the top pick in the 2017 draft, was a reasonable candidate to become the No. 1 prospect in baseball following the graduations of Fernando Tatis Jr. and Vladimir Guerrero Jr. So much for that. Lewis and his altered swing scuffled to the tune of a sub-.700 OPS across High- and Double-A. His walk and power numbers (which weren't outstanding to begin with) each regressed from their 2018 levels, too. Because Lewis is a below-average defender at short, his bat is more important to his profile than the typical middle-infield prospect. As such, the Twins can only hope he can find some mechanics that fit him better ahead of next spring.

Forrest Whitley, RHP, Astros

Whitley's story is similar to Lewis' in that he was considered to be arguably the best pitching prospect in baseball back in spring. And why wouldn't he be, based on his deep arsenal, his starter's frame, and his success in the minors? Alas, Whitley's year didn't play out as planned. He exited the weekend having accumulated an 8.60 ERA -- yes, really -- in 52 innings, as well as 39 walks and 11 home runs. Factor in how he missed more than a month due to injury, and there isn't much positive to be gleaned from this season.

Estevan Florial, OF, Yankees

Speaking of injuries, Florial didn't make his season debut until June due to a broken wrist. It would be understandable if the rust impacted his play but boy oh boy. Despite repeating High-A, Florial walked less often and fanned more often. He did hit for more power, perhaps due to being more pull-heavy, yet his overall seasonal line is just .239/.301/.390. There were already concerns about his bat heading into the year and this effort won't help put those to bed. It's a shame because Florial's secondary tools give him an intriguing ceiling.

Triston McKenzie, RHP, Cleveland

Maybe it's unfair to include McKenzie due to injury, but he hasn't pitched this season and the biggest question mark about him entering the year was his durability. Remember, McKenzie missed a chunk of 2018 due to a forearm issue. He strained his back in spring, and hasn't been seen since. He has a quality arm and a bright future ahead of him if he can stay on the mound, so here's hoping next season is a healthy and fruitful one.

Justus Sheffield, LHP, Mariners

When Sheffield was traded over the winter to the Mariners as part of the return on James Paxton, the hope was that he could step into the big-league rotation sooner than later. Sheffield did make his debut this year; he also struggled in Triple-A -- to the extent that the Mariners demoted him to Double-A, where he made 12 appearances and seemed more in his element. There's no telling what the future holds, but if Sheffield can't improve his command then he may end up in the bullpen.

Now, onto the Watch.

Prospect watch

Right-hander Matt Tabor had himself a season in A-ball, as he entered the weekend with 97 strikeouts (and just 16 walks) in 91 innings.

It's too soon to get too concerned, but Shea Langeliers has struggled to get going offensively. He was the No. 9 pick in the draft thanks to his defensive chops. Still, you have to hit some to reach the majors.

Ryan Mountcastle has more than earned a look in the majors in September. He's hitting over .300 in Triple-A with 24 home runs. His swing-happy approach and defensive limitations means he'll need to keep producing if he wants to stick.

Southpaw Kyle Hart doesn't have overpowering stuff, but he's been able to find success in the upper minors all the same. At some point, the Red Sox owe it to themselves to see if he can walk the thin line in the majors.

The Cubs have in their system a teenage infielder named Pedro Martinez, meaning one day folks might have to clarify which ballplayer with that name they're talking about.

Konnor Pilkington has a tremendous name. Unfortunately, he's run into some trouble in High-A.

Speaking of great names, Packy Naughton's walk and strikeout rates went down divergent paths upon his promotion to Double-A. There's still some hope he can be a back-end starter.

A promotion to High-A hasn't stopped Tyler Freeman from hitting. He might be Francisco Lindor's heir at the shortstop position. 

Roberto Ramos still has an outside shot of finishing the year with 30-plus homers in Triple-A. It's conceivable he finds himself in the majors as a bench bat.

Daz Cameron had one of the most disappointing seasons in the minors. Most expected him to be manning center field for the Tigers by this point. It's hard to blame them for not promoting him, however.

You might recall Jonathan Arauz as a member of the Ken Giles trade. He's in Double-A now, but his bat limits his ceiling. 

Nick Pratto, the 14th pick in the 2017 draft, has had a forgettable year. For his sake, hopefully next season goes better.

Aaron Hernandez, the Angels third-round pick in 2018, has shown the ability to miss bats in High-A. He needs to throw more strikes to stick around as a starter.

Another piece of the Yasiel Puig return, Josiah Gray has quietly authored a good season across three levels.

Nick Neidert is striking out a batter per inning in Triple-A. He's one of the next youngsters likely to get a spin in the Marlins rotation.

Lucas Erceg, who used to be projected as Milwaukee's third baseman of the future, now profiles as more of a bench bat. He had an uninspiring season at Triple-A.

Trevor Larnach has continued to hit in Double-A and could position himself for a late-season promotion next year.

Franklyn Kilome is a name to keep in mind for this system next season. He missed this year due to Tommy John surgery, but he has lively stuff and a starter's frame.

Domingo Acevedo has lost a lot of prospect shine in recent years. Still, it was a little surprising to see him get released.

One of the biggest questions entering the year about outfielder Lazaro Armenteros was whether he strikes out too much to reach the majors. He's fanned in nearly 43 percent of his plate appearances this season at High-A, suggesting the answer is probably yes.

The 14th pick in the draft, Bryson Stott has had little trouble posting good numbers against Low-A pitching.

Outfielder Jared Oliva's speed and defense make him an easy-to-project fourth outfielder. He could be a bit more than that if his bat translates.

San Diego's third-round pick in 2018, infielder Owen Miller has already found success in Double-A. He checks the box on every tool except pop.

Keep outfielder Alexander Canario's name in mind heading forward. He could be a riser on prospect lists.

Right-handed reliever Wyatt Mills has a good fastball-slider pairing and should contribute to Seattle's bullpen next season.

Part of the Oscar Mercado trade, Conner Capel did not have a good year in the upper-minors.

Taylor Walls tends to get overlooked in the Rays system. He's already achieved some success in the upper minors and has four tools that project as average or better.

Bubba Thompson has the potential to fly up prospect lists. Fair to say he didn't show it this year.

Hector Perez could contribute to the Blue Jays staff in 2020. He was part of the Roberto Osuna return.

Speaking of 2020 contributors, Jhonatan German could show up in D.C. as a reliever thanks to his fastball-slider combo.