Let the kids cut out white circles of construction paper. Then punch some holes in them with a paper punch. Give the kids a long string of red yarn to lace through the holes. It really resembles the red laces of a baseball and is great for a fine motor skills activity.
My students love making team pennants for our baseball theme. cut out the shape of a pennant and then you can decorate with icons from their favorite team or even better create their own.
For our sports week we visited our high school baseball field and took a picture of each child on the field. Back at the room we made a baseball card from their picture.