Arguably the most impressive hitter under contract with the Boston Red Sox this season is a 20-year-old who hasn't made his major league debut. Franklin Arias, who some outlets consider to be the Red Sox's No. 1 prospect, was known mainly for his contact abilities and slick defense at shortstop coming into the year. But in his first 20 games of the season with Double-A Portland, he's showcased some impressive power. With eight home runs in those 20 games, including a stretch of seven long balls in nine games, Arias is making a huge impression early, which comes with percolating anticipation for his promotion to Triple-A Worcester, which seemingly could arrive at any moment. If you like our content,  choose Sports Illustrated as a preferred source on Google . Arias raising expectations, setting himself up for promotion Fans watch the Boston Red Sox take on the New York Yankees at the base of the Green Monster April 23 at Fenway Park in Boston.…