It’s easy to see why Guerra was one of the key pieces coming back to San Diego when they dealt Craig Kimbrel to Boston last November. Guerra has double-plus defensive tools that have him projecting as an elite defender at the shortstop position. He has an extreme smoothness to his actions and incredible body control to go with a plus arm and lightning quick first step. His bat, however, is not nearly as advanced, and it will take some time before it catches up to the defense. The ingredients are there however – he has a very simple set-up with little pre-pitch movement, and has a level, line-drive stroke with above-average hand speed. That said, he has had some swing-and-miss throughout his short professional career, with a 112:30 K:BB ratio in 2015 and striking out 23% of the time so far in 2016 (64:15). He appears to be comfortable hitting down in the count, but tends to get passive with his at-bats to a fault at times, not jumping on some mistakes in the zone that he should handle. Some of that I attribute to his low motor, and how easy he makes everything look. Ultimately though, he will need to be more aggressive in the zone, and that should come as he matures and develops his approach.
As is sometimes the case with young players that are plus athletes, Guerra can sometimes get a little too lackadaisical, and lose focus on routine plays that cause some unforced errors (he has 12 errors already through 46 games), and see him give away some ABs. He has never really struggled before, and when you factor that in with this being his first organizational shift and it can be a lot to handle for a young player. While I cannot speak to what that type of pressure feels like, I imagine it can be significant (see Erick Mejia, SS, High A Rancho Cucamonga for a similar scenario).
He has a very slender, wiry frame, but has some muscle structure now and plenty of room to get stronger without sacrificing his athleticism. He hit 15 HRs and 23 doubles last season, so he does have some pop. His slugging is down a bit so far in 2016 (four HRs and eight doubles), but he doesn’t turn 21 years old until September, and he’s still learning how to make adjustments. He doesn’t project to be a huge home run threat, but 10-15 HRs in the big leagues is not a stretch, and should be able to find gaps on a consistent basis. Boston seems to have a knack for finding shortstops with elite defensive abilities like Jose Iglesias (now with Tigers), and Xander Bogaerts. Guerra has a ways to go before catching those two, but it is fun to dream.