The two matches that matter for automatic promotion are of course Villarreal at Barcelona B, and Girona at Almeria. No matter what happens, the race is guaranteed to go down to the last jornada, and one of Villarreal, Almeria, or Girona will win automatic promotion (Alcorcon cannot, regardless of other results)
The brief synopsis: Defeating Barcelona B is of course important, but regardless of the outcome, as long as Almeria gets at least a point against Girona, we will win promotion with a win over Almeria. The worst outcome next week would be for Girona to win in Almeria; if they do, we have to win as well, or else depend on Real Madrid Castilla for help on that final weekend while defeating Almeria ourselves.
First, let's assume Almeria defeat Girona.
(1) Villarreal defeat Barcelona B: a draw with Almeria will see us promoted, unless Almeria defeats Girona by four goals or more. I believe if it is tied in goal difference it come down to most goals scored, which would see Almeria through. Not sure about that. But a loss to Almeria sends them through, for sure.
(2) Villarreal draw at Barca B: Villarreal must defeat Almeria.
(3) Villarreal lose at Barca B: Villarreal must defeat Almeria.
Now, let's consider what happens if the Almeria-Girona match finishes in a draw.
(1) if Villarreal defeat Barca B, a draw with Almeria will see us through regardless of how Girona does at home to Real Madrid Castilla in their last game.
(2) if Villarreal draw with Barca B, Villarreal must draw with Almeria (we would win on goal difference), if Girona draws with RM Castilla, or loses to them. Villarreal must defeat Almeria if Girona wins (otherwise Girona would go up).
(3) if Villarreal lose to Barca B, Villarreal must defeat Almeria.
Finally, let's see what transpires if Girona defeat Almeria.
(1) if Villarreal defeats Barcelona B, we would need to at least draw with Almeria (if Girona draws or loses its last match) or defeat Almeria (if Girona wins its final game)
(2) if Villarreal draws with Barca B, now we need help. If we draw with Almeria, and Girona loses to RM Castilla, we win the tiebreak with Girona. But if Girona gets a result, we are out unless we defeat Almeria as well--then Girona would need to win its last game as well.
(3) if Villarreal loses to Barca B, again we need help. A Girona draw and Villarreal win in the last weekend would give Girona and Villarreal 74 points, and we would go through. A Girona loss puts us through with a win in our last game, but a Girona win puts us out regardless of what happens at El Madrigal. Given what happened the last day of the season last year, I hope we can avoid these last two scenarios!!