Yastrzemski is out of the lineup for Monday's game in Philadelphia.
Lopez (knee) will return from the 15-day injured list to start Wednesday's game against the Rays in Atlanta, Chad Bishop of The Atlanta Journal-Constitution reports.
Ritchie allowed two runs on four hits and a walk over 6.2 innings for Triple-A Gwinnett on Sunday while striking out a career-high 15 batters.
Atlanta manager Walt Weiss said Monday that Elder will temporarily move to the bullpen, Chad Bishop of The Atlanta Journal-Constitution reports.
Murphy is not in the lineup for Monday's game in Philadelphia.
Schwarber went 1-for-3 with a solo home run, a walk and an additional run scored in Sunday's 5-4 loss to Atlanta.
Acuna went 2-for-4 with a home run, a double and four RBI in Sunday's 5-4 win over the Phillies.
Mahle did not factor into the decision in Sunday's 5-4 win over the Phillies, allowing two unearned runs on four hits and one walk with three strikeouts over six innings.
Nola did not factor into the decision in Sunday's 5-4 loss to Atlanta, allowing one run on four hits and one walk with five strikeouts over seven innings.
Iglesias earned the save in Sunday's 5-4 win over the Phillies, allowing one hit and no walks with one strikeout in a scoreless ninth inning.
