BOSTON — Vladimir Guerrero Jr. hit a home run. We’re at the point where that, alone, is worth noting.The Toronto Blue Jays first baseman sent a rising line drive to left field Thursday, clearing Fenway Park’s monstrous left-field wall. He broke into his signature stutter-step, rounding the bases for the first time in weeks, and returned to the dugout for cheers and the series of handshakes he’s been without for so long.The homer, which aided Toronto’s 4-3 win to sweep the Boston Red Sox, was Guerrero’s first in 25 games. It was just his fourth of the year. The Jays hope it’s the swing he’s been looking for. They need that swing back.“It’s gotta be one at-bat at a time,” Guerrero said through team interpreter Hector Lebron. “The better swings, the better pitches that I see, the better selection at the plate, that’s going to start feeling a lot better at the plate.”This hasn’t been a normal Guerrero slump. We’ve seen Toronto’s first baseman struggle for stretches before. Those dips, usually, are filled with 100 mph ground balls and line drives finding gloves. You can usually see the light at the end of the grounder-filled tunnel.Can Trey Yesavage get back on track?Derek VanRiper and Eno SarrisOver the last six weeks, though, Guerrero has been among the worst hitters in baseball by fWAR. His chase rate this year (31.5 percent) is the highest of his career and 10 percent above last season. In the first of a 14-year contract, he’s hitting the ball softer and barrelling pitches half as often. The swings, at times, have looked way off. The light in the tunnel hasn’t been particularly bright.