How does this happen?

Alan Trammel is my starting ss. He gets hurt for 3 games.On my set line ups page I have my back ups listed as Dick Lundy and Martin Dihigo who are rated 1-26 and 2-12 for defense ,but the computer shifts Frankie Frisch my starting second baseman to ss, his def at ss is ~3-31.How can this be?

Is this during the game that Trammell was injured or in the following game?

Bill

The last game on sat, Trammel is hurt and replaced by Lundy . All three games on sunday Frisch starts at SS.

Greg

The way stuff like this happens is:
1.the player listed as 1st backup is in the starting lineup already
2.his (1st backup) backup is also in the starting lineup.

Or

1.the player listed as 1st backup is injured
2.the 2nd backup is in the starting lineup
3.his (2nd backup) is in starting lineup

Or

Both 1st and 2nd backups are injured.