BOSTON -- First baseman Mike Napoli was not supposed to play Wednesday night. He had struck out in all four of his at-bats Tuesday, his average dropping back under .200, he’d had little success in the past against Orioles starter Bud Norris (2-for-15, 8 whiffs), and John Farrell said playing Brock Holt at first base gave him another left-handed bat in the lineup, which he preferred.

But when Hanley Ramirez was injured on a freak play -- he was struck by a line drive hit by Xander Bogaerts on a hit-and-run in the fifth inning -- Holt was moved to left field to take Ramirez’s place and Napoli entered the game at first.

It did not go well. Napoli took a called third strike from Norris in the sixth, then swung and missed at a 3-and-2 pitch from Mychal Givens, a right-hander making his major league debut, in the eighth.

That made it six straight strikeouts from Napoli, his average dipping to .197, his confidence level undoubtedly south of the Mendoza line as well. It seems like a distant memory now, that week in mid-May in which Napoli hit five home runs in a span of six games and seemed to have shed the slump that had held him in its grip for much of the season’s first six weeks.

But that proved to be a temporary respite. Napoli is searching again, batting just .189 (17-for-90) in his last 27 games, striking out 32 times in that span. The same harsh judgments that have been bandied about on David Ortiz when he was slumping have found another target in Napoli, who is in the last year of his two-year, $32 million contract with the Red Sox and offering little incentive for them to re-sign him before he turns 34 on Oct. 31.

But here is one misconception about Napoli’s play this season: It may seem like he’s striking out more than ever, but he’s not. So far this season, he has K’d 26.2 percent of the time. In 2013, his first season with the Sox, that percentage was 32.4 percent.

What is different, of course, is that he is not making the same impact when he does connect. ISO, or isolated power, is the measure of a hitter’s raw power, as measured by extra-base hits per at-bat. It is calculated by subtracting batting average from slugging percentage.

In 2013, Napoli’s ISO was .223. In 2011, when he was with the Rangers and enjoyed the only 30-homer season of his career, his ISO was .312. This season, his ISO is just .181.

Another factor: In 2013, Napoli’s batting average on balls in play (BABIP) was .367; this season it’s .232, which suggests that he may have enjoyed a measure of good luck in 2013 that is conspicuously absent this season.

Regardless of the numbers, however, it is clear that Napoli is currently a mess, which did not look to be the case this spring, when he bashed six home runs in exhibition play.

“This is surprising,’’ acknowledged manager John Farrell, who in Tuesday night’s game dropped Napoli to the No. 8 spot in the order, the first time he has hit that low since 2012.

“There’s going to be swing and miss, we know that with Mike. That’s part of his makeup as a player, with the power you’re going to get. We’re certainly not turning away from Mike, we’re here to help him get through it.”