Is the phrase "spherical ball" redundant?

In a computer science course, our professor was explaining the idea of object oriented programming using the analogy of soccer. While reading the Wikipedia article on Association Football, it said this:

Association football, more commonly known as football or soccer, is a sport played between two teams of eleven players with a spherical ball

If ball is connotated with a round, spherical object, is saying "spherical ball" redundant?

Solution 1:

No, it's clearly not redundant. Compare it with this.

Rugby football, more commonly known as rugby or rugby union, is a sport played between two teams of fifteen players with a non-spherical ball.

Solution 2:

No, it is not redundant.

Although the standard shape conveyed by the word ball is indeed a sphere, the things we call balls have enough variance for the accepted definition to be more lenient than just “sphere”. The NOAD’s first entry for ball defines it as “a solid or hollow sphere or ovoid”. Dictionary.com calls it “a spherical or approximately spherical body or shape”. Merriam-Webster says “a round or roundish body or mass”.

Consequently, in a context such as football where the ball does have varying shapes, it is not redundant to specify that it is a spherical ball and not “an ovoid”, “approximately spherical”, “roundish” or otherwise.

Solution 3:

I would say it is and isn't. In proper english going by dictionary definitions, a ball implies a spherical body or shape.

In "spoken" or common spoken language there are footballs, rugby balls, etc. You could argue that this is a stretch or evolution of the term ball to mean the passable or focused upon equipment of a game, usually somewhat round in shape. Even a badminton's shuttlecock and hockey pucks have circular shapes in their design.