Johnson, 31, landed on the disabled list June 24 (retroactive to June 18) with lower back spasms. The right-handed hitter is batting .271 (49-for-181) with three home runs and 31 RBI in 56 contests for Chicago, recording a .343 on-base percentage. He has made 44 starts for the Cubs, with the club going 30-14 in those games.
Johnson signed with the club March 25 as a free agent after beginning Spring Training with Toronto, and has gone on to bat .376 (32-for-85) with runners on base this season. Johnson has posted a .392 batting average (20-for-51) with runners in scoring position and batted .310 (9-for-29) with seven RBI in 11 June contests. He has recorded 20 RBI in his last 22 games with a plate appearance.
Originally selected by the Toronto Blue Jays in the 17th round of the 1999 Draft, Johnson made his major league debut with Toronto in 2003. He has a .280 batting average (634-for-2,264) with 45 home runs and 265 RBI in 666 career games with the Blue Jays (2003-2007) and Cubs (2008).
Patterson, 25, has batted .237 (9-for-38) with a home run and seven RBI in 13 games over three stints with the Cubs this season. He belted his first major league homer June 22 off the White Sox Javier Vazquez at Wrigley Field. With Iowa this season, Patterson is hitting .323 (61-for-189) with 13 doubles, three triples, six homers, 28 runs and 27 RBI in 49 games.