Toro, who is batting .179 with six homers and 13 RBI, was injured in Saturday’s loss when he collided with right fielder Adam Frazier going after a pop-up in the first inning, hitting the ground after a catch.
The 33-year-old Souza appeared in just six games, going 3 for 19.
To take their place, they recalled outfielder Taylor Trammell and selected utility player Sam Haggerty from Triple-A Tacoma.
Seattle enters Sunday having lost 18 of its last 24 games and has dropped the first three of a four-game series against the Red Sox.
Braves and Dodgers meet in series rubber match
Los Angeles Dodgers (44-26, first in the NL West) vs. Atlanta Braves (42-31, second in the NL East)
Cardinals and Cubs meet to decide series winner
Chicago Cubs (27-45, fourth in the NL Central) vs. St. Louis Cardinals (41-33, second in the NL Central)
Brewers and Blue Jays play, winner takes 3-game series
Toronto Blue Jays (40-31, third in the AL East) vs. Milwaukee Brewers (41-33, first in the NL Central)
White Sox aim to break 4-game slide, play the Orioles
Baltimore Orioles (34-39, fifth in the AL East) vs. Chicago White Sox (33-37, third in the AL Central)
Mariners try to prolong win streak, take on the Angels
Seattle Mariners (34-39, third in the AL West) vs. Los Angeles Angels (34-40, fourth in the AL West)
Rays play the Pirates after Arozarena's 4-hit game
Pittsburgh Pirates (29-42, third in the NL Central) vs. Tampa Bay Rays (39-32, fourth in the AL East)