San Diego Padres catcher Benito Santiago, who hit safely in 34 straight games to establish a first-season record, was a unanimous selection as the Jackie Robinson rookie of the year in the National League, the Baseball Writers Association of America announced yesterday.

Santiago, who batted .300, hit 18 home runs, drove in 79 runs and stole 21 bases, received 120 points. Runner-up Mike Dunne, a pitcher for the Pittsburgh Pirates, had 66 points -- drawing 22 second-place votes. St. Louis Cardinals pitcher Joe Magrane finished third with 10 points.

Two writers from each of the league's 12 cities participated in the voting, which was conducted at the end of the regular season.

Santiago, a native of Puerto Rico, became the fifth NL rookie to be acclaimed unanimously. The others were Frank Robinson, Cincinnati, 1956; Orlando Cepeda, San Francisco, 1958; Willie McCovey, San Francisco, 1959, and Vince Coleman, St. Louis, 1985.

Mark McGwire of the Oakland Athletics was named AL rookie of the year on Tuesday and he, too, was a unanimous selection . . .

First baseman Willie Upshaw had arthroscopic surgery to remove bone fragments from his right knee, the Toronto Blue Jays announced.

Upshaw, 30, is expected to be fully recovered for spring training. He hit .244 with 15 home runs and 58 RBI in 150 games in 1987.