Dilshan will return to Sri Lanka to lead the national side against England.
Dilshan, who was recently appointed as Sri Lanka's captain for all three formats, featured in his last game of the tournament against Kochi Tuskers Kerala.
Dilshan struck an unbeaten half-century to make it a memorable exit.
"Yes, Dilshan has played his last game. It's difficult (to find a new opening pair). That partnership (Gayle and Dilshan) which we put together certainly has enabled us to win these last five games. We have got a couple of options and we got to make a decision pretty quickly.
"When you look at the foreign players there is Thomas Pommersbach and Rilee Rousouw or look at a guy like Saurabh Tiwary to come up the order. He hasn't had much batting, so it might be a good opportunity for him to get some balls under his belt which will be beneficial to us," Vettori told reporters at the post-match press conference.
Dilshan was keen to spend some time in England before the warm up against Middlesex at Lord's on May 14.
Vettori was full of praise for Chris Gayle, who blazed his way to 16-ball 44 to set up the easy win.
"It's all him out there. I sit back and just enjoy, I know it's more enjoyable because he is on my side. But I think that's why people love Twenty20 cricket. Gayle, what he did tonight, 37 runs off one over, I am sure it's been never done before. It's amazing knock," he said.
With five wins in a row, Bangalore are now third in the points table but skipper is targeting a top-two finish.
"We want to finish as high as possible in the points table because there is certainly some advantage if you finish first or second. We know we have to play well in the remaining four games to try and get there. I think one win is irrelevant now, we have to try and finish as high as possible," noted the Kiwi.
The left-arm spinner had a word of praise for seamer Sreenath Arvind, who returned good figures of two for 20.
"Wicket was a lot drier than it was the other night. Arvind has been bowling amazingly in the last two or three games, so he is just continuing on his good form. The wicket certainly helped us but we were able to take control of those conditions.
"I think taking wickets in this format has such bearing on run-rate and dictate the terms. At times Zaheer and Mithun were very good. Chris did his job and pretty pleased to dismiss a good team to 120 odd runs," he added.