The move comes at a time when Seattle ranks near the bottom of the American League in almost every offensive category. Through 63 games this season, the Mariners were hitting .248 (13th), scored 253 runs (13th) and possessed a Major League-low .305 on-base percentage.
"It's all about results," general manager Bill Bavasi said of his reasoning behind the move. "That's probably the biggest thing. We felt like this crew had underperformed for a long time. This isn't new."
Pentland was in the middle of his third season with Seattle and had been the only holdover from last season's seven-man coaching staff. During his first two seasons with the club, the 61-year-old dramatically improved the overall production of his hitters.
Seattle's team batting average went from .256 to .272 during his first season on the job. In 2007, there was another increase in production, with the team's average rising to .287.
That type of improvement was exactly what Seattle's management had been waiting for again this year. Unfortunately there came a point in time when the team decided a change needed to be made.
"We kept having the thought that we would turn this around, because we believed in [Pentland] and we know he's a really good hitting coach," Mariners manager John McLaren said. "We just kept thinking that today's the day we can start to get something going -- start swinging the bats like we're capable of doing -- and it just didn't happen. It reached a point where we thought we had to move forward."
The move comes less than a week after team president and CEO Chuck Armstrong was overheard having a heated discussion with the coaching staff behind closed doors. The fact that a move eventually was made didn't come as a surprise to many players inside Seattle's clubhouse, but that didn't make the news any easier to take.
"We all have to hold ourselves accountable," said left fielder Raul Ibanez, who is hitting .262 with eight home runs and 39 RBIs. "The way we've hit is not Jeff Pentland's fault -- it's the players. ... It's a tough thing when you know that if you had done more, you would have helped save his job."
With almost 100 games remaining in the season, there is plenty of time to fix what's been wrong. Elia will be the man in charge of making sure that happens.
The 70-year-old had been working as a special assistant to McLaren, and on average, he spent 10 days a month with the team. The Mariners think his familiarity with the club's hitters should help make for an easy transition.
The veteran coach, who has been around professional baseball for 47 seasons, is an emotional guy who isn't afraid of getting in the face of one of his players when he thinks it's necessary. For now, though, Elia said his top priority is to get his hitters to be a little more selective at the plate and lock into a particular zone where they can drive the ball.
"There are some things that I'm more profound in [than Pentland], and that's mostly in the approach to hitting," Elia said. "You can't change the old habits of a hitter or anybody else in what they do in life, but if we can kind of tighten up some of their thinking, maybe we'll be better off in the big picture."
The fact that Elia accepted the promotion comes as somewhat of a surprise, because during Spring Training he stressed that he wasn't interested in becoming more than a part-time instructor.
That changed when Bavasi got in touch with him on Sunday night and informed him a move was going to be made. Elia recognized the need for the Mariners to have an experienced person step in right away and finish the season with the club. That brought about a change in heart, at least somewhat.
"I'm still not interested in it," Elia said with a laugh. "I'm a Seattle Mariner guy. I've spent 10 lovely years here. We've been going through a little bit of a tough time right now. ... I discussed it with my wife and daughters, and it's not like I'm going away for 100 years. I'll be up here for a little while."
Gregor Chisholm is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.