Another week, another fantasy baseball stock watch report! This week we are taking a look at a mix of young players and more established players who got off to slow starts. In all sports, but more specifically baseball, a small sample can change a player’s perceived fantasy value very quickly. With how quickly values can change, it is always incredibly important to stay on top of whose value is changing and why, both for trades and waiver wire pickups.Without further ado, let’s dive in! Interested in sports betting? Tell us what YOU want from a mobile sportsbookFantasy Baseball Trade Value: Stock risingJordan Yamamoto, SP, Marlins. Yamamoto was a 12th-round pick and was ranked as the No. 17 prospect in Miami’s organization, so when he got called up there wasn’t a whole lot of excitement in the fantasy community. However, he has been fantastic in his first three starts in the bigs (19 IP), compiling a 0.95 ERA, a 0.79 WHIP, 19 strikeouts, and a 3-0 record. He pitched well at AA prior to his call-up, too, compiling a 3.58 ERA, 1.19 WHIP, and an 8.8 K/9 across 65.1 innings. When digging deeper into his profile, we quickly see a mixed bag of results. His .167 BABIP against is extremely lucky and will go up, and his 45.2-percent hard-contact rate against is very high and also pointing toward luck being on his side. However, he has induced soft contact at a 31-percent rate, which would easily be the best in baseball with enough innings to qualify, and he has given up line drives at a 16.7-percent clip, which would be sixth best in baseball. He doesn’t have an overpowering fastball at 91 mph, but he does have a six pitch mix that allows him to keep hitters off balance. It’s also important to keep in mind that he will pitch half his games in Miami, which ranks as the best pitchers park in all of baseball when it comes to home runs.Lourdes Gurriel Jr., 2B/OF, Blue Jays. Gurriel Jr. hit so poorly (.175, zero home runs) in his first 13 games this year that it led to a demotion to AAA, where he stayed for over a month. Most fantasy owners cut him and rightfully so, but since being recalled on May 24 he has been playing great, hitting .330 (37-for-112) with 10 home runs across 29 games. Last season, he had 11 home runs across 249 at-bats, so what has led to his 10 home runs across 152 at bats this season? The key cog is a change in approach. He is hitting fly balls 10-percent more often, and he has upped his launch angle from 10.4 degrees to 14.6 degrees this year. For a guy who hits for hard contact over 40 percent of the time, getting lift on the ball will almost certainly result in hitting home runs at a pretty good rate. He should continue to be a strong fantasy asset, and the fact that he is hitting third in the Blue Jays lineup on a daily basis is perfect for fantasy purposes.Yasiel Puig, OF, Reds. Puig had been dreadful for the majority of the season, hitting just .207 through his first 59 games. He did have 11 home runs and nine stealss, but a .207 batting average is still a category killer in fantasy. However, he is smoking hot right now, hitting .400 (18-for-45) with five home runs, 11 RBIs, and two steals over his past 12 games to raise his season average up to his current .240 mark. With 16 home runs, 11 steals, and 44 RBIs, he is currently on pace to put together a 30-20 campaign with 90 RBIs, and that’s nothing to scoff at. That would give him new career highs in all three of those categories. Similar to Gurriel Jr., Puig has changed his approach this season. He is hitting fly balls at a career high 47.2-percent rate (11-percent more often than last year), and his 18.4-degree launch angle is a six degrees increase from last year (which was his highest mark prior to this season). The buy-low window is gone, and we can expect Puig to continue to find success with the Reds and the hitter’s dream park that is the Great American Ball Park.MORE: Fantasy Alarm PRO toolsFantasy Baseball Trade Value: Stock fallingVladimir Guerrero Jr., 3B, Blue Jays. Vlad hasn’t quite been the immediate big bat that everyone expected him to be, as he is hitting a poor .255 with seven home runs and 21 RBIs across 188 at bats and 49 games played. He has also struck out (40) far more often that he has walked (18), which is a far cry from what he was doing in AAA. Unfortunately for his owners, the underlying stats aren’t showing a guy who has been unlucky. In fact, they show a guy who needs a major change in approach. Sure, his 40.3-percent hard-contact rate and 90.8-mph exit velocity are both strong, but that doesn’t do him a whole lot of good when he has a dreadful 6.8-degree launch angle and is pounding the ball into the ground 48.3 percent of the time. His 17.4-percent line-drive rate and 34.2-percent fly-ball rate are both lousy, especially when considering the type of hitter he is supposed to be. Right now is the perfect time to buy low on Vlad in fantasy, as a quick turnaround could take place at any moment.Zach Davies, SP, Brewers. Davies got off to a torrid start this year, pitching to a 1.54 ERA and a 5-0 record through his first nine starts. However, the wheels have completely come off in his past six starts, as he has a 5.76 ERA in that span with hitters batting .336 against him. The biggest issue for Davies is simple: He does not have very good “stuff”, and he can’t strike any one out. His velocity ranks in the fourth percentile, as he rarely hits 90 mph on the gun and his 5.79 K/9 is the second worst in all of baseball (Brett Anderson takes home the crown with an unsightly 4.57 K/9). Pitching to that much contact is going to lead to a lot of hits and a high WHIP (currently 1.36). Maybe he could get away with being a contact pitcher if he was in a pitchers park but Miller Park ranks as a top-10 hitters park. Robinson Canó, 2B, Mets. Cano’s first season with the Mets has been flat-out awful. He is hitting a dreadful .223 and has just four home runs and 16 RBIs through 54 games despite hitting third on a team that ranks in the middle of the pack in runs scored this year. He has been unlucky, though, with a .263 BABIP and a batting average .045 points lower than his xBA. That being said, even if he wasn’t unlucky this year, he would still have the stats of a bad player. There are a lot of factors working into why he has fallen off a cliff this year. His 5.6-percent walk rate is his lowest mark in 10 years, his 19.5-percent strikeout rate is the highest of his entire career (and it isn’t even close), and his 50.9-percent ground-ball rate is dreadful (especially for someone as slow as he is – 15th percentile in sprint speed). His 5.8-degree launch angle is barely half of the league average (11.0). To put it simply, Cano is a shell of his former self and is not going to do your fantasy team any favors.Fantasy Baseball Stock Watch: Potential waiver wire pickupsFrancisco Mejía, C, Padres. Here we go again with Mejia. After starting the year as the Padres backup catcher and struggling to the tune of a .167 batting average with zero home runs through 19 games, Mejia was sent down to AAA. While at AAA he hit .365 with four home runs across 63 at-bats. While he was plugging away at AAA, Austin Hedges continued to be the Padres starting catcher, but he has been dreadful this year with a .195 average and six home runs across 174 at-bats. Looking for a spark at the catching position, the Padres recalled Mejia on June 20, and he immediately started the next four games. In those four starts, he went 5-for-15 with a home run and had a hit in every game. While the production has been good, the biggest key is that he drew four straight starts and that is what should draw your attention. The catching position is a wasteland in fantasy, especially in deep two-catcher formats, so why not take a shot on a guy who was a top-50 prospect each of the past three years?Trent Thornton, SP, Blue Jays. Thornton has been a very interesting case this year, and in fact this is the second time he has landed in this section. He has been a mixed bag of results this year with a 4.25 ERA, 1.40 WHIP, and 9.5 K/9. The ERA and WHIP aren’t great, but the strikeouts are strong and he has pitched very well against two of the league’s top offenses in Houston and Boston in his past two starts. Against Houston he fired 6.2 shutout innings and then followed that up with 6.1 innings of two-run ball against Boston. Back-to-back outings like that against those offenses is something that gets my attention. His next start will come against another elite offense in the Yankees and if he is able to pitch well once again, it will be time to start taking Thornton a little more seriously.