Ross, 36, suffered the injury during yesterday's game against the Blue Jays at Fenway Park. He has gone 9-for-43 (.209) with a double, four home runs, five RBI, eight runs, and seven walks in 15 games for the Red Sox this season. Ross leads all catchers with at least 15 games played with a 2.64 catcher's ERA and has thrown out four of 14 attempted base stealers (28.6 percent).
For the 25-year-old Lavarnway it marks his second stint with Boston this season. He was previously with the club April 25-27, but did not appear in a game. Lavarnway has played in 21 games for the PawSox this year, with 19 appearances at catcher and two at designated hitter. He has hit .321 (25-for-78) with seven doubles, two home runs, 15 RBI, 16 runs, and 13 walks, including a .333 mark (10-for-30) with eight RBI in eight games in May. He has thrown out seven of 15 attempted base stealers (46.7 percent), the best rate among International League qualifiers. Lavarnway has played in 63 career major league games with Boston, all over the 2011-12 seasons, going 33-for-192 (.172) with 10 doubles, four home runs, and 20 RBI. He will be active for today's game against Toronto at Fenway Park.