BOSTON -- Mookie Betts awoke in Seattle on July 25, the morning after the Boston Red Sox were held to four hits and shut out for the ninth time in 101 games, and tweeted a picture of himself with David Ortiz. The last line of Betts' 94-character caption, complete with emojis and a hash tag, seemed to reflect the mood of the team.

I miss you big bro

Six weeks later, the Red Sox are in the pole position in the American League East. But if they hold off the New York Yankees and claim their second consecutive division title, they will have done so in a different fashion than at almost any time in their history. The days of pounding opponents into submission with home runs went away with Ortiz. These Red Sox win with pitching, defense and by running the bases like daredevils.

Betts personifies that aggressive, up-tempo style. He was supposed to fill the middle-of-the-order power vacuum when Ortiz retired after last season. After all, Betts had just come off a year in which he bashed 31 homers en route to being runner-up to Mike Trout in the AL MVP race. And at age 24, the star right fielder is still getting stronger.

Instead, Betts was stuck on 18 homers for 144 plate appearances until he went deep Friday night in the first inning of a 9-3 victory over the Tampa Bay Rays. It was only his third homer since the All-Star break, leaving him on pace to finish the season with 21. Moreover, his .779 OPS ranks 88th among 152 players with enough at-bats to qualify for the batting title in either league.

Strictly from an offensive standpoint, the drop-off has raised questions about whether Betts merely had a career year last season.

Warning-track power Mookie Betts' at-bats per home run and home runs per fly ball, now and then: 2016 2017 Pre-Break 2017 Since AB per HR 21.7 22.1 69.7 HR per FB 14.3% 13.1% 4.9% Source: ESPN Stats & Information

"Mookie is one I would not worry about," says one National League scout who recently saw the Red Sox. "The man can play."

Indeed, Betts has still piled up 5.5 wins above replacement, based on calculations by Baseball-Reference.com, fifth most among AL position players. That's a testament to Betts' defense and baserunning.

Entering Friday night, when he made a stellar running catch in the first inning, Betts led all players with 29 defensive runs saved, according to Baseball Info Solutions, three shy of his majors-leading total from last season. In addition to stealing 23 bases in 26 attempts, he paces the Red Sox with 20 bases taken on fly balls, wild pitches, passed balls, balks or defensive indifference. And he has succeeded in advancing more than one base on a single or two bases on a double 68 percent of the time, which also leads the team.

Consider the effect Betts had on Tuesday night's game against the Toronto Blue Jays. After ripping a double in the ninth inning, he dashed to third base on a grounder to third baseman Josh Donaldson, which enabled him to score the tying run one batter later on a groundout. In the 19th inning, Betts made an astute read on Hanley Ramirez's bloop single to center field and scored the winning run from second base in a 3-2 victory.

"I'm just trying to affect the game in some way whenever I get an opportunity," Betts says. "If that's stealing a base, making a catch, beating out a double play, whatever it may be."

Betts' ability to be a difference-maker even when he's struggling at the plate has kept him in the lineup, too.

At various times this season, Red Sox manager John Farrell has attempted to jump-start a slumping player by giving him a two- or three-day mental break. It happened with center fielder Jackie Bradley Jr. in May, left fielder Andrew Benintendi at the end of July and recently with shortstop Xander Bogaerts and rookie third baseman Rafael Devers. Not Betts, who has started all but two of 52 games since the All-Star break despite batting only .244 with 16 extra-base hits and a .663 OPS.

"He impacts the game so many different ways," Farrell says. "The defensive side of it is a key component to it, and when he does get on base, he's a threat, obviously. He's been a major player for us."

But if the Red Sox are going to make a legitimate run at the World Series, they need Betts' bat to heat up, which brings us back to Ortiz.

Big Papi's absence has been felt in many ways.

The Red Sox miss his plus-sized personality, including his booming laugh and frequently off-color sense of humor. There was a magnetism about Ortiz. He always drew the spotlight, thereby shielding his younger teammates from bearing the full brunt of the glare in a sports-obsessed market that expects its teams to win all the time.

Ortiz had a similar influence in the middle of the order. Until his final game, he was among the most feared sluggers in baseball, a force to be reckoned with whenever he came to the plate. The mere specter of having to face Ortiz with runners on base in a close game changed the way teams approached pitching to everyone else in the Red Sox's lineup.

David: "I'm going way back today!"

Me: 😂😂 (He never disappointed me) I miss you big bro #Pun pic.twitter.com/1qlu8mDo3k — Mookie Betts (@mookiebetts) July 25, 2017

Without Ortiz around, opponents have shifted their focus to Betts.

"There's a guy, No. 34, not in that lineup anymore, and as a pitcher, you work them different without the big man in there," the NL scout says. "The league has adjusted to [Betts], and he will adjust back."

Specifically, Betts has seen more sliders -- one out of every five pitches, according to FanGraphs, compared with 17.8 percent of the time last season. Betts is known for his lightning-fast hands, and teams seem to be more cognizant of his ability to turn on inside pitches. As a result, pitchers have attacked him on the outside part of the plate and even off the plate.

Mostly, though, Betts simply isn't getting as many pitches to hit. Through Thursday, only 43.4 percent of the pitches he saw were in the strike zone, down from 47.6 percent last year and 49.1 percent in 2015. And although his strikeout total has remained low and he continues to make consistent contact, he also hasn't driven the ball with as much authority. If anything, Betts has been more prone to popups than the average major league hitter.

"If they pitch him in the zone, he's going to hit," Red Sox hitting coach Chili Davis says. "The problem is, when they start teasing you outside your zone, how far outside your zone are you going to go? When he's not feeling good at the plate, he tends to go a little too far outside his zone."

Betts has a simpler way of explaining it.

"Just not being consistent, not swinging at good pitches," he said recently. "Pretty much doing a whole bunch of things you're not supposed to do. Just got to work on getting it right."

Here's the good news for the Red Sox: Betts and Davis say they believe they found the answer.

For weeks, Davis believed Betts' stride length was the problem. But during a recent video session, they agreed that it was Betts' balance that was out of whack. In an attempt to reach pitches on the outer half of the plate, he was lunging too far and actually moving away from the ball.

"The pitches that he got to easily -- the inside pitch, the middle pitch and even the pitch away -- he wasn't getting to any of them," Davis says. "His swing got long, and then he couldn't get to the ball inside. And even if he got hits, the ball wasn't jumping off his bat. Once he straightened that out, he was getting to the ball inside. And then the sliders he was on, he stayed with them longer and he could hit them wherever he saw them."

Five days ago, Davis says Betts emerged from batting practice by declaring, "Man, that's the best BP I've taken in a long time." Sure enough, Betts has six hits, including three doubles and a home run, in his past four games.

"I think I'm coming around," Betts says, "getting better day by day."

In spring training, Betts told anyone who asked that he wouldn't use last season as a bar to measure his goals for this year. The implication was that even he suspected he would be hard-pressed to have another 30-homer output.

Farrell says he doesn't believe last season was an outlier. Neither does Davis. Betts doesn't profile as a prototypical slugger, but the Red Sox are confident he will once again show middle-of-the-order power even without Ortiz around to provide cover for him.

"It's tough to match [last year's] numbers, but the feel and the consistency can always get better," Davis says. "Mookie is a perfectionist. I think that's what makes him so good as a player. Where others might look at him and go, 'Man, you're having a nice year; it's not last year, but you're swinging good,' he's going to respond with, 'Yeah, but I don't feel right.'

"For me, what I'm disappointed in is that it took us so long to get to what could make him feel comfortable. But hey, it's a learning experience for everybody. Hey, I had sleepless nights, too."

And while the Red Sox wait for Betts' bat to fully awaken, they will happily take his game-changing defense and baserunning.

"People have to remember it's a tough game and guys don't always rake every year," says the NL scout. "They can trade him to my team any time they want."