Tommy Watkins believes several members of the Salt River Rafters, the team of prospects he will lead in the Arizona Fall League championship game Saturday, will reach the major leagues next summer.

But he’ll be there before them.

The former Twins infielder and minor league manager was hired as Minnesota’s next first base coach, the Twins announced Friday. Watkins and Tony Diaz, a longtime coach in the Rockies system hired to coach third base, are the latest additions to new manager Rocco Baldelli’s staff. Earlier this week, pitching coach Wes Johnson and assistant pitching coach Jeremy Hefner were named to the staff, which has just one vacancy remaining.

“It’s very exciting. It kind of caught me off guard a little bit, but I’m very grateful for the opportunity,” said Watkins, whose MLB career amounted to nine games — and a .357 batting average — in 2007. “The emotions of [being promoted] are just as high as when I was called up as a player.”

After 12 years in the Twins system, Watkins, 38, ended his playing career in 2009 and embarked on a coaching career, first as hitting coach in Class A, where Eddie Rosario, Byron Buxton and Miguel Sano were among his first pupils. He was named manager at Class A Cedar Rapids in 2017, promoted to Class AA Chattanooga last year, and has handled the Twins’ Arizona Fall League entry for the past six weeks.

In addition to his first-base duties during Twins games, Watkins will coach the team’s outfielders and first basemen.

“Rocco was an outfielder, so I’m looking forward to getting his input and help in working with them,” Watkins said. “I’ve coached quite a few of the [current Twins], so it’ll be good to get into a rhythm with them and get to work.”

Diaz, 41, has a similar history with one franchise — but it’s Colorado. The Twins lured him away from the Rockies, an organization with whom he spent 19 seasons, by making him third-base coach, after spending two seasons as first-base coach in Denver. The hire adds a second Spanish speaker to the Twins staff, along with assistant hitting coach Rudy Hernandez. Diaz, in fact, is the author of “Practical English for Latin Players,” a manual the Rockies use to help prospects adapt to living in the U.S.

Diaz has six years of managing experience in rookie leagues.

The Twins also hired Billy Boyer, an assistant coach at Seattle University, to be their minor league infield and baserunning coordinator. A former minor league infielder in the Angels system, Boyer, 34, replaces former Orioles manager Sam Perlozzo, who is being promoted within the Twins system.

Prospects update

Six Twins prospects, led by Class AA outfielder Jaylin Davis, play for East Division champion Salt River, which meets Peoria for the Arizona Fall League title in Scottsdale on Saturday. It may only be a developmental league, Watkins said, but “the winners do get rings. Every ballplayer wants to play for a ring.”

Watkins, who manages a team composed of players assigned from the Twins, Diamondbacks, Marlins, Rockies and Nationals, will be trying to capture the ninth championship by a Twins affiliate in the Arizona Fall League’s 27-year history.

Minor leaguers signed

The Twins have begun stocking their system for 2019, adding three minor league free agents and re-signing two members of their 2018 Class AAA team. Righthander Ryne Harper, a reliever with six saves and a 3.60 ERA at two levels, and catcher Wynston Sawyer, who was sidelined for 10 weeks with a fractured hamate bone, will return to Class AAA Rochester.

In addition, the Twins agreed to minor league contracts with Randy Cesar, an infielder in the Astros system, and two righthanders who made major league appearances in 2018: Zack Weiss (3-3, 5.40 in the Reds’ system) and Preston Guilmet (a 6.00 ERA in 11 total innings with the Blue Jays and Cardinals).