Some players available on a free this summer are:

Jed Wallace (Millwall he is a decent winger and the championship has given Palace good signings Eze and Olise.)

Eddie Nketiah (Palace always linked with him can you see it happening?

Yakou Meite (decent player for Reading another winger signed new contract 2023 recently but with Reading debt problems he probably won't cost more than £10m.)

Boubakar Kamara (can play CB but predominantly CDM Marseille man available on a free can PV persuade him to come to Palace?)

James Tarkowski (out of contract this summer)

Jesse Lingard (free this summer)

Noussair Mazaroui (very good player plays LB and RB well an area that will make Palace stronger especially with Ferguson injury problems him and Tyrick would make Palace stronger.)

You have to think the end of this season will be a time of reckoning for Nathan Ferguson. For all the occasional positive PR speak, the fact is that he's been out of the game for two years now and he's entering the last year of his contract this summer. If he'd played and proven himself now is the time we'd be offering him a new deal. If he'd played well and increased his value, this is the summer we'd be thinking about selling him on or fighting to keep him. What's clear with Ward and Clyne ageing and Ferguson now no more than a marginal prospect for the long-term, we desperately need to bring in a right-back. That should be a priority this summer.

My guess is that we hold on to Ferguson and hope he starts next season fit because we have nothing to lose. He's unsellable now. But two years out of the game and multiple injuries, you can't be confident about his future. Optimistic, maybe, but not confident. If the first half of next season doesn't see him in the number 2 shirt every (or most) weeks, my guess is he'll be off in the January window or at the end of next season when he's out of contract at the latest.

As for the others on your list, I have minimal interest in Nketiah. Maybe he'll make it, but I wouldn't throw an enormous contract at someone with so much to prove. Thus far, there's been a lot more hype than delivery. On a reasonable contract, worth a chance but I wouldn't get into a bidding war or make him a top priority.

Lingard, on the other hand, I wouldn't mind. Gallagher's departure will leave a hole and ditto McArthur is ageing. Lingard is at least the sort of productive, forward-driving, and experienced proven player who could contribute something. He might not be everyone's first choice, but we could do a lot worse.

A player to cover defence and Keeper, now that'll be a find
Assuming you meant Guehi, not sure we need a youngster, but definitely need cover of some kind. Not been that impressed with Tomkins in PV's system..

As others have mentioned, a RB should be priority.
would be surprised if we didn't bring in another 2 players on top of that though.

I suspect a large number of supporters would be in agreement.

Moving on to central defence, I do believe that we need to find a young player to step in should Guaita or Andersen get injured.
I have been impressed with Levi Colwill who is on loan to Huddersfield from Chelsea.He is left-footed and has played predominently on the left of a back three at Huddersfield.He is a modern-day central defender who is calm and composed on the ball.

I think Ferguson will be the CD cover if he ever gets fit, or of course if it is easier to find a DM then Kouyate can revert to his natural position. if he extends his contract of course, i think he seem younger than his age, another 2 years

I have serious doubts to whether Nathan Ferguson will ever be the player he was pre knee injury.

Knee injuries ruin careers.

Recently, you only have to look at Connor Wickham to see what a knee injury can do to a player.

Going back over the years you can take plenty of examples. Man City had an extremely gifted player in Paul Lake whose career was cut extremely short through knee injuries.

Going back further we had Kevin Mabbutt who had to retire through a knee injury.

The other issue is that Ferguson doesnt play in flair position, his main duties will be tackling, jumping etc. That is going to put more strain on the body. Hence why he is breaking down.

Will be a terrible shame if he doesnt make it, but he isnt first and wont be the last through a knee injury.