Rafael Benitez's efforts to rebuild his Newcastle squad for life back in the Premier League are being hampered by his failure to offload some of the men bought for a promotion push. The Spaniard was allowed to spend heavily by second-tier standards last summer as he re-invested much of the proceeds from the sales of Moussa Sissoko, Georginio Wijnaldum and Andros Townsend to assemble a group of players to mount an ultimately successful title charge.Some of those players - most notably Matt Ritchie, Isaac Hayden and Dwight Gayle - will play significant roles in the top flight, but others find themselves surplus to requirements with the likes of Grant Hanley and Achraf Lazaar, as well as Emmanuel Riviere and Henri Saivet, who were inherited by Benitez, having been told they can leave.However, Press Association Sport understands that while there has been interest in some of those men, the lucrative wage deals which saw them move to St James' Park have proved a major obstacle to their departure.Owner Mike Ashley, who insisted in the wake of promotion that his manager would receive "every penny" the club generated from promotion and player sales, has always sought value for money during his tenure and the prospect of paying salaries to squad members who have little chance of involvement is not an appetising one.Benitez, not for the first time this summer, admitted his frustration at his struggles after Sunday's 2-0 friendly victory over Hellas Verona.He said: "When I decided to stay, I was expecting another thing. Now we are where we are. I decided to stay because of a lot of positive things I could see, starting with the fans."I will try to do my best to be sure that the team we have will be good enough to compete and stay as high as we can in the Premier League."Newcastle's need for a proven striker in particular was illustrated when last season's leading scorer Gayle sat out with a hamstring issue which has been a concern for some months, and their interest in Stoke's Joselu and Arsenal's Lucas Perez has so far come to nothing.With around three weeks of the summer transfer window remaining, there is still time for Benitez to both offload some of his unwanted players and land his remaining targets, although his need to do so will become all the more pressing as the days go by.The club have so far completed a permanent deal for loan signing Christian Atsu and brought in Florian Lejeune, Javier Manquillo, Jacob Murphy and Mikel Merino, but the manager is still looking for up to three more signings to make the Magpies competitive.