Red Sox activate Johnson, option Betts

The Red Sox optioned outfielder Mookie Betts to Triple-A Pawtucket before Thursday's game at the St. Louis Cardinals in order to make room on the 25-man roster for Kelly Johnson, whom the Red Sox activated off the 15-day disabled list.

Betts, 21, is hitting .244./.279./.266/.645 in 44 plate appearances in 13 games for Boston in 2014.

Johnson, whom the Red Sox acquired in a July 31 deadline-day trade with the Yankees in exchange for Stephen Drew, will wear No. 7, the same number Drew (and Drew's brother, former Red Sox outfielder J.D., before him) donned for Boston.

Johnson, 32 is not in Thursday's starting lineup, but is expected to be available off the bench. In 77 games this season with the Yankees before landing on the DL with a strained left groin, Johnson has a .219/.304/.373./677 line with six home runs and 22 RBIs in 227 plate appearances. He's a career .251/.333/.424/.758 hitter in nine years for the Yankees, Tampa Bay Rays (2013), Toronto Blue Jays (2011-12), Arizona Diamondbacks (2010-11) and Atlanta Braves (2005, 2007-09).

UPDATE (8:19 p.m. ET): Thursday's game began after a rain delay of one hour and four minutes, with Mike Napoli starting at first base instead of David Ortiz. Boston's revised lineup:

1. Brock Holt RF

2. Dustin Pedroia 2B

3. Yoenis Cespedes LF

4. Mike Napoli

5. Xander Bogaerts SS

6. Christian Vazquez C

7. Jackie Bradley Jr. CF

8. Will Middlebrooks 3B

9. Brandon Workman P