A strobel for an article of footwear comprises a polymeric bladder that defines an interior cavity. The polymeric bladder is configured to retain a fluid in the interior cavity. The polymeric bladder has a peripheral flange extending around at least a portion of a perimeter of the interior cavity. The peripheral flange defines a groove extending along the peripheral flange. The polymeric bladder may include a first polymeric sheet bonded to a second polymeric sheet at the peripheral flange and joined to the second polymeric sheet at a plurality of interior welds. Methods of manufacturing a strobel and manufacturing footwear are included.