Contreras has missed the team's last 27 games as he dealt with a strained hamstring, but after several rehab outings over the last week the catcher will be back behind the plate for Jon Lester's start on Tuesday night at Wrigley Field.
The catcher has hit 19 home runs and driven in 57 RBI's this season, batting .275 for the year. He will bat sixth in the team's lineup.
Batting in the lead-off spot, Zobrist will make his first appearance since May 7 when the Cubs take the field Tuesday. The infielder has not played in a game since he was placed on the restricted list in May, but will make his big return as the Cubs try for the two-game sweep over the Mariners.
First pitch is scheduled for 7:05 p.m., and the game will air on NBC Sports Chicago.