MINNEAPOLIS — Hardly anyone calls Willians Astudillo, the charismatic backup catcher and utility player for the Minnesota Twins, by his given name anymore.

His manager, Rocco Baldelli, doesn’t even try. To Baldelli and others, Astudillo is la Tortuga, Spanish for the Turtle, or even just Tortuga. It’s much more fun to say anyway.

Astudillo (pronounced AS-too-DEE-yo) can’t remember who gave him the nickname, or when. But it’s easy to see how he got it.

At 5 feet 9 inches and 225 pounds, Astudillo resembles a Teenage Ninja Turtle come to life, albeit one who can play eight positions and reliably put the ball in play. His Twins are the surprise of the season, on pace for the best record in franchise history and leading the majors in home runs, runs scored and batting average. And while he may not the biggest contributor to the team — Jorge Polanco has a team-leading .925 on-base-plus-slugging percentage and Jake Odorizzi is 10-3 with a 2.58 E.R.A. — his everyman persona and uncanny bat control has made Astudillo one of the most popular Twins.