As for the Master [of Avis], whom we left in Alenquer, he sent men out to spy on the King of Castile, after they told him that he was in Guarda. This was in order to find out the strength of the army that was accompanying him and what route he was intending to take. Some days before King Juan arrived at Santarém, a message reached the Master, informing him that he was heading straight there, that his forces were somewhat scattered and that there were not many with him.

The Master told Nuno Álvares that the King of Castile was heading down through the country and would very soon be in Santarém, adding that he thought it best for them to return to Lisbon, in order to ensure all due protection for the city. Nuno Álvares answered that, even if they went back to Lisbon, the King of Castile would know the route to take to attack the city just as well as they, whose duty it was to defend it. Rather, his advice was that, while the King of Castile was advancing with a relatively small force, and before heavy reinforcements could join him, a watch be kept on his movements, so that, when he reached the Santarém area, they could block his approach and engage him in battle; that way they could easily defeat him and such a victory would greatly advance the Master's cause.

The Master declared that this was excellent advice but that it could not be achieved without danger to himself, as their own numbers were very small. At this point he received another message, telling him that the King of Castile was due to reach Santarém that very day. Consequently, the Master set off with his forces and made his way back to Lisbon.