Southend United have made changes to their strike force by signing Scott Spencer and releasing Alex Revell.Spencer, 21, has signed a six month deal with an option for a further year, having been on trial from Rochdale. [LNB]Meanwhile Alex Revell has had his Southend contract cancelled by mutual consent, and has now agreed to sign for League One rivals Wycombe Wanderers. [LNB]Wanderers are now waiting for approval from the Football League before the deal can be confirmed. [LNB]Revell had been on loan at Swindon since September, but a permanent move failed to materialise. [LNB]He scored four goals for Southend after signing from Brighton in January 2008. [LNB]Spencer is a product of the Everton youth system, and was released by Rochdale in 2009, when he joined Southend on trial.