Crystal Palace have been priced out of a move for Mamadou Sakho with the club’s new manager, Frank de Boer, confident he can recruit up to five players for a combined outlay close to Liverpool’s £30m asking price for the France defender.

There had been initial optimism within the Palace hierarchy that Sakho’s loan move, which was so key to Sam Allardyce’s team securing their top-flight survival last season, could be made into a permanent transfer. Yet Liverpool, who have welcomed the centre-back to Melwood of late to continue fitness work after a knee ligament injury curtailed his eight-game spell at Palace, have as yet refused to drop their valuation of the player.

That has prompted the London club, who appointed De Boer last week, to cast the net wider. There is interest in the Ajax and Holland defenders Joel Veltman and Kenny Tete, with the latter having been granted permission to miss the Dutch team’s pre-season training camp in Zillertal to hold talks with other clubs. Veltman is with the 25-man Ajax party in Austria, where they will play Werder Bremen in a friendly on Saturday. That pair would cost in excess of £10m.

Palace have lost Fraizer Campbell, Joe Ledley, Mathieu Flamini, Jonathan Benteke and Zeki Fryers under freedom of contract – the left-back has since joined Barnsley – and an option to make Loïc Rémy’s loan from Chelsea a permanent deal was not taken up after his injury-wrecked campaign. Their departures have left the squad distinctly thinner, in particular in central midfield and up front, though De Boer is determined to assess those he has inherited before deciding where else to strengthen.

The club are in the process of confirming the make-up of his backroom staff, with at least two coaches expected to join and Sammy Lee, Martyn Margetson and Ryland Morgans, recruited under Allardyce, to begin the campaign under the new regime. Their presence would assist the transition though, if all parties click, that arrangement would be extended for the longer-term.

The manager has spoken at length with Jason Puncheon, who ended last season as captain, and been hands-on around the club’s Beckenham training centre since his arrival last Monday. Players such as Scott Dann and James McArthur may seek reassurances over their futures after both endured frustrating seasons, albeit largely because of injury, last time round.