Point currentFrame = нужный кадр анимации.  
Point frameSize = размер кадра анимации
Rectangle rec = new Rectangle(currentFrame.X * frameSize.X,
currentFrame.Y * frameSize.Y,
frameSize.X, frameSize.Y)

public Texture2D[] Split(Texture2D original, int partWidth, int partHeight, out int xCount, out int yCount)
     {
         yCount = original.Height / partHeight;//The number of textures in each horizontal row
         xCount = original.Width / partWidth;//The number of textures in each vertical column
         Texture2D[] r = new Texture2D[xCount * yCount];//Number of parts = (area of original) / (area of each part).
         int dataPerPart = partWidth * partHeight;//Number of pixels in each of the split parts

         //Get the pixel data from the original texture:
         Color[] originalData = new Color[original.Width * original.Height];
         original.GetData<Color>(originalData);

         int index = 0;
         for (int y = 0; y < yCount * partHeight; y += partHeight)
             for (int x = 0; x < xCount * partWidth; x += partWidth)
             {
                 //The texture at coordinate {x, y} from the top-left of the original texture
                 Texture2D part = new Texture2D(original.GraphicsDevice, partWidth, partHeight);
                 //The data for part
                 Color[] partData = new Color[dataPerPart];

                 //Fill the part data with colors from the original texture
                 for (int py = 0; py < partHeight; py++)
                     for (int px = 0; px < partWidth; px++)
                     {
                         int partIndex = px + py * partWidth;
                         //If a part goes outside of the source texture, then fill the overlapping part with Color.Transparent
                         if (y + py >= original.Height || x + px >= original.Width)
                             partData[partIndex] = Color.Transparent;
                         else
                             partData[partIndex] = originalData[(x + px) + (y + py) * original.Width];
                     }

                 //Fill the part with the extracted data
                 part.SetData<Color>(partData);
                 //Stick the part in the return array:                     
                 r[index++] = part;
             }
         //Return the array of parts.
         return r;
     }

Texture2D spriteSheet=Content.Load<Texture2D>("Run");
int xCount,yCount;
Texture2d[] parts = Split(spriteSheet, 10, 10, out xCount, out yCount);
///
///...
///
parts[frame].GetData(runnerData);