Updated

Boston Red Sox ace Clay Buchholz will miss at least another week due to a strained neck that has landed the majors' current leader in earned run average on the disabled list.

The Red Sox announced the move, made retroactive to June 9, prior to the second game of Tuesday's doubleheader with Tampa Bay.

Buchholz did not make his last scheduled assignment because of the injury, which occurred during a win over the Angels on June 8. He had been slated to pitch Saturday against Detroit, with manager John Farrell announcing that either Allen Webster or Ruddy De La Rosa will make the start in his place.

The right-hander is in the midst of an outstanding 2013 campaign. Buchholz has posted a 9-0 record along with an MLB-best 1.71 ERA through 12 outings this season, while yielding just 57 hits in 84 1/3 innings. The Red Sox have won all but one of his starts.

Boston also placed backup catcher David Ross on the 7-day concussion list for the second time this year before Tuesday's nightcap. The 36-year-old, who's hitting just .185 with two home runs in 23 games, initially began experiencing concussion symptoms after taking a pair of foul balls off his catcher's mask in a May 11 game against Toronto.

Catcher Ryan Lavarnway was recalled from Triple-A Pawtucket to replace Ross, with pitcher Alex Wilson summoned from the PawSox to fill Buchholz's roster spot.

Lavarnway batted .157 with two homers and 12 RBI in 46 games for the Red Sox last season. Wilson made 17 relief appearances for Boston earlier in the year, going 1-1 with a 2.61 ERA.