The answer is a pretty straight forward no. By the time that Henry Tudor was making his play to take the throne from Richard, he was the senior legitimate claimant from the House of Lancaster following the death of Henry VI and his children, was invested in the conflict, and was backed by France and most of the remaining Lancastrians both in exile and in England. Simply put, there was really no one else for Lancastrians to rally behind anyone else. Though technically the claims from the House of Aviz or the House of Trastamara (Castile) were stronger, neither of them were in any position to make good on those claims when Henry did. Portugal and Castile had engaged in a war in the latter half of the 1470s and Isabella of Castile was far more focused on consolidating her throne, reforming her kingdom, and completing the Reconquista than pursuing potential conquests in England. She was also already married, leaving her without the prospect of a marriage to a British noble to further secure any potential control over the throne in the event of a military conquest. Similarly, John II of Portugal was too concerned with bringing his own nobility in line and expanding the overseas holdings of Portugal in Africa to turn around and attempt to make good on the English throne. Its doubtful John II would'v even had the necessary resources and/or clout to rally the Lancastrians and follow through with an attempt at conquest without seriously jeopardizing the position of Portugal. Not to mention that neither Isabella or John were actually English, which would've made it even harder for them to rally the Lancastrians, especially when someone like Henry Tudor still existed.

Sources:

Henry VII; The Maligned Tudor King - Terry Breverton
Elizabeth of York; The First Tudor Queen - Alison Weir
A Short History of Henry the Seventh - James Gairdner