It's time to do some catching up with catcher prospects. Every year it seems that catcher prospects have the most dramatic changes — both positive and negative — in their perceived value and potential out of any other position player prospects. This year is no different, as some former first-round picks now teeter on the edge of irrelevancy while previously unknown players are becoming popular names in conversation when discussing prospects.

Looking at catchers in particular, it is sometimes difficult to gauge their potential and value. In 2017, MLB catchers hit .246 — the lowest average among position players excluding designated hitters — and had a cumulative .726 OPS — also the lowest among position players. So, the catchers that make it to the majors because of their offensive prowess are very valuable commodities in fantasy baseball, and should be scooped up as soon as possible.

All six of these players have the potential to make it to the major leagues within the next few years, it will just be a matter of whether it's for their glove or for their bat.

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Stock Rising

Keibert Ruiz, Los Angeles Dodgers

In just three years, Ruiz has rocketed up prospect ranking lists to become not only one of the top prospects in the Dodgers' organization, but one of the top catcher prospects of any organization. Splitting time between Low-A Great Lakes and High-A Rancho Cucamonga, Ruiz hit .316 with 23 doubles, eight home runs and an .813 on-base plus slugging percentage. While his strikeout rate did rise slightly from 2016, it was still at a low 12.9 percent.

What's really promising for Ruiz is he has increased his line drive percentage each season since signing with the Dodgers in 2015. Ruiz has gone from 14.2 percent of his batted balls being line drives to 19.1 percent to 22.5 percent in 2017. If he continues to hit line drives at this rate, he should be able to continue hitting in the .310 to .330 range.

As a 19-year-old who is looking like he'll start 2018 with Double-A Tulsa, his potential ceiling makes him one of the most interesting catching prospects in the league right now. Fantasy owners in deep dynasty leagues: if you don't have him now, acquire him before his value gets even higher.

Sean Murphy, Oakland Athletics

A third-round pick in the 2016 Draft, Murphy is quickly blazing a path to the starting job in Oakland. Murphy hit .250 last year with 13 HR and a .723 OPS in 98 games between High-A Stockton and Double-A Midland. While he struck out more and drew walks at a lower pace in his second year in the minors, Murphy was able to maintain slightly above average numbers with a 17 percent strikeout rate and 8.1% walk rate.

It's not outside the realm of possibilities to see Murphy end up in Oakland at some point this year if he can put up numbers similar to or better than his 2017 season. Of the three catchers currently on the Athletics' active roster, Bruce Maxwell was the only one with at least a .205 batting average in 2017 and he was also the only one with at least a .600 OPS. While it's unlikely Murphy will have any fantasy impact this year barring injury, he could be fighting for the starting job in 2019.

Austin Allen, San Diego Padres

Allen had a power explosion in the California League in 2017, as he more than doubled his career home run total with 22 HR, while raising his slugging percentage almost 70 points from 2016. He also hit a career-high 31 doubles, and while his 21.1 percent strikeout rate was a career-worst he was able to raise his walk rate to a respectable 8.5 percent over 516 plate appearances.

Allen should be able to maintain his career .289 average as he rises through the minors based on the increasing rate at which he is hitting line drives while cutting down on ground balls. His line drive percentage has increased in each of the last two seasons, going from 16.5 percent in 2015 to 21.1 percent to 24 percent last year. Meanwhile he has drastically reduced his ground ball percentage from 55.1 percent in 2015 to 37.1 percent in 2017.

He will be with the Padres in Spring Training as a non-roster invitee, which will provide a good glimpse of how he can perform against major league talent. Comparing his numbers to those of current San Diego starting catcher Austin Hedges' minor league career, Allen so far has put up better stats across the board. While the Padres are likely going to stay with the 25-year-old Hedges for the foreseeable future, Allen could be the backup to Hedges very soon and could be competing for the starting job within a year or two if Hedges struggles.

Stock Falling

Nick Ciuffo, Philadelphia Phillies

Drafted in the first round of the 2013 Draft and believed to be one of the best offensive high school catchers chosen that year, Ciuffo has not seen that offensive potential translate into success at the professional level. While a career .248 average could be forgiven in this day and age if he was putting up big power numbers, but 12 career HR — seven of which came last year — are not enough to ignore the low average.

At this point, it appears that Ciuffo's defense will be what potentially gets him to the majors. While he did show some improvement in 2017, including posting a career-high .704 OPS, he still has a lot of work to do before he can regain any potential fantasy value he might have had when he was drafted.

Meibrys Viloria, Kansas City Royals

After tearing up the Pioneer League in 2016 and being named MVP, fantasy owners were hoping to see Viloria carry over that success at the next level. Instead, Viloria posted career-lows with a .259 average, a .313 OBP and a 6.3 percent walk rate with a career-worst 19.8 percent strikeout rate. He also recorded a .707 OPS — the second-lowest mark of his career just ahead of his .595 OPS from 2015 when he had zero extra base hits.

Probably the biggest concern for Viloria is his high propensity for hitting ground balls. In three of his four seasons of pro ball, at least 50 percent of his batted balls were ground balls, and in the fourth season he had a ground ball rate of 49.5 percent. Last season in the South Atlantic League, Viloria's 56.8 percent ground ball rate was tied for the sixth-highest among batters with a minimum of 350 plate appearances.

Viloria turns 21 in just a few weeks, so he still has time to turn things around and recapture the success he had in 2016. For now though, his value is dropping and if he doesn't show improvement this year his chances of reaching the major leagues will rapidly diminish.

Jose Trevino. Texas Rangers

Trevino followed up the best season of his career in 2016 with the worst season of his career in 2017. His average dropped 62 points from .303 to .241 while his OPS dropped from .776 to .598 — both career-lows. Trevino's .275 OBP and .323 SLG also ranked in the bottom-five in the Texas League among qualified batters.

What's most puzzling about Trevino's 2017 season is that while his average and OPS both dropped, so did his strikeout rate — albeit ever so slightly. After posting a 10.5 percent strikeout rate in 2016, Trevino posted a 10.4 percent strikeout rate last season to mark his third consecutive season in which he has lowered his strikeout rate. And looking at his batted-ball tendencies, while his 48 percent ground ball rate is still high, it was down from the 50 percent rate he had during his career year in 2016. Trevino also increased his line drive rate from 16.7 percent to 18.6 percent, which should have potentially improved his average rather than dropping it.

Before last season, it appeared that Trevino was on track to appear in the majors relatively soon. This  sudden drop off in production now presents a major roadblock for the 25-year-old, and he could soon find himself lost in the depths of the minor leagues if he can't turn things around.

More 2018 MLB Prospects Analysis