Willson Contreras doesn’t do many things quietly.It didn’t take long for the Boston Red Sox to find that out. In spring training, teammates nicknamed him Bowser, after the fire-breathing dragon from the Mario Kart series. In the first home series of the season at Fenway Park, he got into a shouting match with the Brewers, and his younger brother, William, a catcher for Milwaukee, had to walk him down the first-base line after he was hit by a pitch.The Red Sox were sporting batting practice Bowser T-shirts with Contreras’ No. 40 shortly thereafter.“If you play against me and you don’t like me, that’s fine with me, but at some point if we play together you’re going to love me,” Contreras said in early January, a prescient statement from the veteran player during his first media session following his trade from St. Louis to Boston. Contreras had to waive his no-trade clause this winter for the deal to be completed, noting his desire to play in Boston. “I play to win, I don’t play to mess around,” he said. “I don’t play to make friends on other teams.”Contreras has lived true to those words and then some in skirmishes with the Brewers, then the New York Yankees, and most recently with the Washington Nationals, a benches-clearing fracas that erupted when Washington starter Cade Cavalli shouted at Contreras to, “Sit down, boy!” after striking him out.The Red Sox are a young team, still searching for their identity and still reeling after a brutal start to the year, which saw manager Alex Cora and six coaches fired in April. Contreras, proud and passionate, has filled a void.Willson Contreras landed in Boston after waiving his no-trade clause this winter. (Nam Y. Huh / Associated Press)“He’s a tone-setter for us,” said third baseman Caleb Durbin. “And the confidence and swagger that he brings to the game every single day, we all feed off of that.”But Contreras is not just the fiery leader of a club struggling for consistency. In the midst of a tumultuous year for the Red Sox, he is putting together the best season of his career at age 34.His .285 average and .921 OPS mark career-bests. He’s already hit 20 home runs, matching his season total from last year. There’s little doubt he’ll surpass his career high of 24.On Tuesday, Contreras found out he would replace Vladimir Guerrero Jr. on the American League All-Star roster. The following day, Contreras announced he would participate in the Home Run Derby. (That night, he fouled a ball off his foot, but later told reporters in Chicago that he was generally unconcerned, according to MLB’s Ian Browne.)Contreras has stabilized Boston’s defense at first base, a position he transitioned to just last year. His intense style of play coupled with his powerful bat has resuscitated a Red Sox season on life support.“How he plays the game, his presence in the lineup, what he can do with the bat, the power,” interim manager Chad Tracy said. “You want that in there with the defense. The example he is, because of how hard he plays the game, he means a lot to us.”