"I think sometimes, just being an honest person, sometimes I might take an at-bat with me out to the field," said Brentz, who was a compensation-round pick (36th overall) in the 2010 First-Year Player Draft. "I've done a very good job of separating those at-bats from defense, [but] sometimes I still let it get to me. It's about being a complete player ... you want to have a good stick and a good glove. That's the thing."
Through the ups and downs, he has been a two-time Minor League All-Star and four-time Player of the Week.
Brentz is wrapping up a long season. He logged 122 games at Double-A Portland, hitting .296 with 17 home runs and 76 RBIs while striking out 130 times. He ended the year with Pawtucket, which won the International League championship and lost to Reno in the Triple-A World Series.
Saguaros manager Jason Wood said it's a mindset that comes from within a player to disassociate offense from defense.
"You go from the offensive standpoint to the defensive stand," Wood said. "It's two different parts of this game.
"He's got experience. He knows what he needs to do within himself to be better defensively, and he's working on it. I think the biggest thing for him is he's openly admitted to it, that he can't take that offense out there with him. And that's just part of learning."
Through Wednesday, Brentz had played in 11 AFL games, collecting a .286 batting average and seven RBIs. But even when he is not satisfied with his plate appearances in a game, he's finding ways to let it go.
"We've had enough at-bats now, where it's part of the game," he said. "You're going to have bad games; you're going to have good games.
"But I think it's like when you mess up, when you get the 3-1 pitch or the 2-0 pitch you've been looking for, and you miss it and then you take that out there with you. I think that's what happens. That's the biggest thing, but it's all about learning and growing as a player."
Every aspect of his game needs work, Brentz said. He is learning how to make adjustments at the plate but hastened to add, "First, I need to take more pride in my defense."
As for his No. 4 ranking in the Red Sox system, he said it carries weight with him because he has worked hard and is being noticed. Overall, however, making it to the Major Leagues has everything to do with performance.
"A lot of guys are not on the prospect list, and they make it to the big leagues, and a lot of guys who are on the prospect list, they make it, too. So it does make you feel good that you're on that list, but we're still working hard to get up to the big leagues."
Red Sox hitters in the Fall League
Michael Almanzar is the son of former Major League pitcher Carlos Almanzar (1997-2005). A first baseman from the Dominican Republic, he has played with Class A Advanced Salem in 2012 and reached base safely in 16 consecutive plate appearances during one stretch. In 124 games with Salem, he hit .300, an 80-point jump from his half-season at Greenville in 2011. He is batting .234 in 13 Fall League games.
Christian Vazquez, a catcher, was a ninth-round pick (292nd overall) in the 2008 Draft. After almost five seasons in the Minors, he advanced to Double-A this season, appearing in 20 games and batting .205. Through his first eight games in the Fall League, he was hitting .259.
Red Sox pitchers in the Fall League
Brock Huntzinger, a third-round Draft pick (114th overall) in 2007, has paid his dues in the Minors. He was called up to Triple-A Pawtucket late this season, pitching in two games. Used almost exclusively as a starter through 2011, he was shifted to the bullpen this year. This is the right-hander's second season in the Fall League, where, through Wednesday, he had an ERA of 3.00 in six games (0-1) with eight strikeouts in nine innings.
Chris Martin signed as a Minor League free agent in 2011, having previously pitched for Grand Prairie of the Independent American Association. The lanky right-hander (6-foot-7, 175 pounds) initially was chosen in the 2005 Draft by the Rockies in the 21st round (627th overall). Through Wednesday, he had pitched in seven games this fall, going 1-0 with a 3.38 ERA, walking just one while fanning 12 in 10 2/3 innings.
Ryan Pressly was an 11th round pick (354th overall) in the 2007 Draft. He split time between Salem and Portland in 2012 -- posting 5-3 and 2-2 marks, respectively -- and posted a 2.93 ERA at Triple-A in 14 games out of the bullpen. In nine innings over seven games with the Saguaros, the right-hander has a 3.00 ERA with 10 strikeouts but has allowed 12 hits.
Pete Ruiz is 26-18 over five years in the Minors. He was 5-2 and picked up five saves with a 3.14 ERA at Salem in 2012 after a callup from the Rookie League. In 48 2/3 innings, he racked up 51 strikeouts. He has pitched in seven Fall League games and has struck out 15 in 9 2/3 innings.