Thanks for your replies @cuonghle and @chr_sue. Just want to make it clear that I am trying to run different sequences on the same sequencer. I think the title of this post causes confusion. My apologies for this.
In my situation, I have an interface (let’s call it intf_A) via which a bunch of setup needs to be done before the actual DUT traffic is sent. This I intend to do in the configuration_phase. When the real traffic starts executing in the main_phase, it’s possible that there needs to be some updates done via intf_A based on certain events. So basically I need to have another sequence running in main_phase for intf_A.