The local church is the pillar and ground of the truth. Since Christ leads His church with the truth, and since there is only one truth (one faith), the church is to unify around the truth (Eph. 4:5, 13). This includes unifying in how ministry is accomplished and who is sent for greater ministry. Individuals do not send themselves; the church sends them.
Paul and Barnabas were sent by the church at Antioch (Acts 13:1-4), and later Paul and Silas were sent (Acts 15:40). Paul sent Titus to minister to the saints at Corinth, and he also sent a brother whose name is unknown: “And we have sent with him the brother, whose praise is in the gospel throughout the churches” (II Cor. 8:18). Earlier Timothy had been sent to Corinth (I Cor. 4:17) and later was sent to Philippi (Phil. 2:19). Tychicus was sent to Ephesus (Eph. 6:22) as well as to Colosse (Col. 4:8).
People can have a desire for greater ministry, but that desire must be tempered with the wisdom and authority of the church, led by the pastor. When this is done properly, the Word of God is honored and Christ is glorified. When it is not done properly, the ministry is harmed.