He can do this all day

Simple yet effective protection deck for Cap, should be best for solo play. With his Shield he already has 3 DEF, and with Armored Vest he cen already mitigate a good amount of damage. Energy Barrier will mitigate another damage to trigger Unflappable and your Hard to Ignore. The latter should help workign against threat without needing to rely on your allies too much, but thanks to Fearless Determination Cap can thwart for 3 in a round too, if necessary. Dauntless, Captain America's Shield and Energy Barrier can accumulate a lot of retaliation damage per round. Apart from that, there are ample ways to stun the enemy (i will exchange Mockingbird with Professor X once I tap into Mutant era for a confusion application) to give you a breather: -Mockingbird -Never Back Down -Iron Fist -Heroic Strike

So apart from stacking upgrades, defense and stun, the main tactic is to use Caps' skill to discard a card and have him do at least his standard action once per turn, thus not losing out on your turn after defending. Unflappable and Avengers Mansion will get you some additional cards for that purpose. Later this will also help using a Shield Toss, if there are minions around. A The Night Nurse and a Med Team can aid you stying ready to act or heal your allies.

Desperate Defense could easily be swapped out, the new Ready for a Fight could combo well with Steve's Apartment, drawing another card, potentially healing, playing an ally cheaper, and getting a full hand of 6 cards, yet still being able to block the next turn. Need to try that, might be worth playing more than 1 Ready for a Fight.