Youkilis, 33, has started 18 games at third base for the Red Sox this season, and has hit safely in eight of his last 13 contests, going 12-for-44 (.273) with two home runs and nine RBI. He is 14-for-64 (.219) with two doubles, two home runs, nine RBI, 14 runs and five walks overall in 2012. A three-time All-Star who was selected by the Red Sox in the eighth round of the 2001 First-Year Player Draft, Youkilis owns a .288 career average (941-for-3,270) with 234 doubles, 16 triples, 131 home runs, 559 RBI, 583 runs, 485 walks and 26 stolen bases in 929 career games with Boston.
Middlebrooks, 23, is slated to make his Major League debut tonight with a start at third base. He is pacing the Red Sox farm system and ranks second in the International League with nine home runs and 27 RBI in his 24 games with the PawSox this year. A right-handed batter, he is tied for the IL lead with 31 hits and also places among the league’s leaders in slugging (3rd, .677), total bases (3rd, 63), runs scored (T-4th, 18) and batting average (T-9th, .333, 31-for-93). He tops all International League third baseman with 24 games at the position in 2012, and also leads that group with a .978 fielding percentage (1 error/46 chances) and six double plays. Selected by the Red Sox in the fifth round of the 2007 First-Year Player Draft, Middlebrooks has hit .276 (428-for-1,550) with 102 doubles, nine triples, 52 home runs, 269 RBI, 223 runs, 128 walks and 35 stolen bases in 416 career minor league games.
Mortensen has allowed just one earned run (2 total runs) over six relief appearances with the PawSox this season for a 0.90 ERA (10.0 IP). He has 10 strikeouts compared to four walks and is holding opponents to a .143 average (5-for-35). Acquired from Colorado in January, the right-hander posted a 3.86 ERA (25 ER/58.1 IP) and 30 strikeouts while going 2-4 over a career-high 16 Major League appearances (six starts) in two stints with the Rockies in 2011. The 27-year-old held opponents to a .257 average (55-for-214) in the Majors last season, including a .240 mark (30-for-125) against right-handed hitters. Selected by St. Louis in the supplemental round of the 2007 First-Year Player Draft, he has appeared in 24 Major League games (13 starts) with the Cardinals (2009), Athletics (2009-10) and Rockies (2011), going 4-8 with a 5.12 ERA (54 ER/95.0 IP) and 50 strikeouts, including a 3.71 ERA (11 ER/26.2 IP) in 11 Big League relief appearances.
The 24-year-old Anderson appeared in six games with the Red Sox after he was recalled on April 23, playing four games in left field (1 start) and two at first base while going 1-for-8 with a run scored. He played in 15 games with Pawtucket to start the season, batting .255 (14-for-55) with five doubles, a homer, eight RBI, seven runs and 10 walks. Selected by the Red Sox in the 18th round of the 2006 First-Year Player Draft, Anderson has appeared in 30 Major League games with Boston over the last three seasons, hitting .167 (8-for-48) with a double, four RBI, seven runs and seven walks.