Houston Astros: Trusting Ken Giles with the closer's role
The Astros added Joe Smith and Hector Rondon to the relief corps and also have Brad Peacock and Collin McHugh pitching in relief thanks to their abundance of starting pitching options.
However, they're still entrusting Giles with the closer job.
The 27-year-old is a strikeout machine and he had a terrific regular season. But manager A.J. Hinch completely lost faith in him during the playoffs, and there's no telling how he responds.
For a team with legitimate hopes of repeating, upgrading in the ninth inning might have been wise.
Los Angeles Angels: Not acquiring a proven closer
The Angels figure to be one of the most improved teams in baseball with a full season of Justin Upton, the additions of Zack Cozart and Ian Kinsler and a starting rotation that is finally healthy.
But who's going to close games?
Blake Parker, Cam Bedrosian and Keynan Middleton are currently penciled into the closer and setup roles on Roster Resource. That trio has a combined 20 career saves.
Jim Johnson is the most proven option on the roster, but he was just 22-of-31 on save chances with a 5.56 ERA for the Braves last season.
Oakland Athletics: Trading Heath Fillmyer
It was tricky to find a move the A's might regret.
Selling high on Ryon Healy with his lack of on-base ability or defensive position was a smart move, the Stephen Piscotty trade could be an absolute steal and the Yusmeiro Petit signing looks like money well spent.
Keep an eye on right-hander Heath Fillmyer, who was sent to Kansas City in the same deal that brought Brandon Moss and controllable reliever Ryan Buchter to Oakland.
The 23-year-old had a solid season in Double-A and has middle-of-the-rotation upside if he can improve his overall command.
Seattle Mariners: Not addressing the starting rotation
Marco Gonzalez should not be relied on as the No. 5 starter on a team with playoff aspirations.
Behind the unproven left-hander, the Mariners have a stable of uninspiring depth options, including Andrew Moore, Rob Whalen, Chase De Jong, Ariel Miranda and Hisashi Iwakuma if he can get healthy.
Beyond that, Felix Hernandez is not the pitcher he once was in the No. 2 starter spot, and both Mike Leake and Erasmo Ramirez look better at the back of a rotation than in the middle.
I'm not sure they've done enough to keep pace in the AL West.
Texas Rangers: Relying on Delino DeShields Jr. as an everyday player
The Rangers have tried this once before.
After Deshields' impressive rookie season as a Rule 5 pick in 2015, the Rangers handed him a starting job the following season.
He responded by hitting .209 with a 55 OPS+ and ended up spending a good chunk of the season in the minors.
As a result, the 25-year-old began last season on the outside looking in, but he eventually played his way into a starting job and now is really the only viable option to play center field on the roster.
Source : http://bleacherreport.com/articles/2759303-predicting-each-mlb-teams-most-crushing-offseason-regret695