The Magpies boss felt his side struggled in the first half at Goodison Park and has urged his men to respond against West Brom
Steve McClaren warned it will take time for Newcastle United's new signings to gel after seeing his side soundly beaten 3-0 at Everton on Wednesday.
Relegation-threatened Newcastle were among the more active teams in the transfer market by bringing in Andros Townsend, Henri Saivet, Jonjo Shelvey and Seydou Doumbia during the window to boost their chances of Premier League survival.
But Newcastle, who are 18th, struggled on Merseyside with Aaron Lennon's first-half strike and two late penalties from Ross Barkley completing a comfortable evening for the hosts.
Three of the four signings started for Newcastle - including a debut for Townsend - while Doumbia was an unused substitute, and McClaren acknowledges the new boys new time to settle.
"In the first half we were never really in it. The crowd and the players here were nervous but we did not capitalise on that," he told BBC Sport.
"Unfortunately we then had injuries in defence which meant we had to reshuffle. The new signings will take time to gel."
Newcastle were hindered by injuries to Chancel Mbemba and Paul Dummett, while a late sending off for Jamaal Lascelles has further depleted McClaren's defensive options.
McClaren, though, urged his team to show fight in the battle against the drop and is demanding a reaction at home to West Brom on Saturday.
"At West Brom we will have 52,000 cheering us on and we will have to show a reaction. We have shown we can react before," he added.
"Fans want to see fight and we need to show it on Saturday."
- Goal