Keates, who watched as Jon Guthrie bagged two second-half goals to take his side close to stealing a point from the travelling promotion chasing Pompey, praised the Saddlers for their work-rate but admitted that they ultimately fell to defeat due to individual errors.
The result sees the Saddlers slip back down to 19th in the League One table, putting them just two points above near-rivals Shrewsbury Town (20th) and 21st-placed Oxford United.