Nationals lefthander Ross Detwiler, taken sixth overall last June, and Rangers outfielder Julio Borbon, taken 35th, both were assigned to high Class A to begin the season. Each is on his club’s 40-man roster, Detwiler by virtue of being called to the majors last September to pitch one inning of relief, and Borbon because he was one of four ’07 picks to sign big league pacts.

Detwiler will open with Potomac of the Carolina League, while Borbon embarks for Bakersfield of the California League.

We learned last week that high Class A also will be the April destinations for two other ’07 draftees: righthander Rick Porcello (Tigers) and lefty David Price (Rays), the No. 1 overall selection. Like Borbon, Porcello and Price were signed to major league deals, as was Yankees righthander Andrew Brackman, who’s slated to miss the season after having Tommy John surgery.