Reading pair Sean Morrison and Jordan Obita have both signed new contracts at the Madejski Stadium.
Ipswich defender Aaron Cresswell has signed a two-year extension to his contract.
Everton boss David Moyes fears he may have to sell players to keep pace in the Barclays Premier League.
The Toffees can finish no higher than their current seventh as they wrap up their campaign with a visit from Newcastle on Sunday.
That would match last season's effort but Moyes reluctantly feels it may take some shrewd buying and selling to maintain that position or make the next step.
The Scot said: "You never want to lose the players you have got, they are vitally important. We've brought them here, nurtured them, brought a lot of them on and we hope we are able to keep them.
"We might now be in a situation where we have to start trading players more than we would like to - but that is the way things go.
"We do a lot of work behind the scenes to prepare so if we can get a situation where we can go and do a bit of business, we will try to do as well as we can."
Moyes endured more than two years of frustration in the transfer market - relying on loans and cut-price or free deals - before last January due to financial restrictions at the club.
But in the last transfer window he was able to prove how adept he can be by bringing in Darron Gibson and Nikica Jelavic, as well as Steven Pienaar on loan, to kickstart his side's hitherto stuttering season.
Moyes said: "In the last window we bought well and showed we didn't need a great deal of cash to turn things around.
"We sold Diniyar Bilyaletdinov and with that money brought in Gibson and Jelavic, and Pienaar on loan.
"I have really enjoyed the way we have played since January, it has given me a great thrill. And more so because I feel I have been able to give the supporters something back.
"At the start of the year I don't think I would have come and watched - there was nothing to excite me. People were saying we were dull, but there is nobody that wants to see attacking play and goals more than me."
When it comes to player trading, Moyes believes there is no better example of how it can be done than Sunday's opponents Newcastle.
The Magpies travel to Goodison Park hoping to wrap up a superb campaign by securing a Champions League qualifying place.
Newcastle were relegated three years ago but have come back strongly with this season's surge fuelled by the likes of Papiss Cisse, Demba Ba and Yohan Cabaye, all of whom have been signed since last summer.
The major difference between the clubs from Moyes' point of view is that Newcastle's recruitment was funded by the £35million sale of Andy Carroll.
Moyes said: "They got a big buy off Andy Carroll which gave them some cash to go and spend and it changed things around.
"That gave them the opportunity to do that and they have spent it very well.
"I don't think you need to break the bank but you have to do things within your means and that is what we have done.
"There is a bit of similarity with how we did it in the early days when we sold Wayne Rooney and had to go out and purchase some players and bring them on.
"I think you do need to have that lump some to go and start your work and that can kickstart things. Newcastle have done really well this year."
Moyes is pleased that his side have not lost ground this season but he will not be happy until they are challenging for honours.
He said: "I said if we finished in the top 10 that would an acceptable achievement. But I don't think you ever want to be saying finishing 10th - or seventh - is that good.
"The only place you want to finish is first, although maybe in the Premier League it is slightly different because getting in a Champions League spot is seen as success.
"I wouldn't say 10th is successful, I would say it is adequate. But from where we were in the summer, and the amount we spent, it is a decent return for us."