Spin wizard Muttiah Muralitharan may be an obvious choice on the difficult Eden track but with Vettori back after a hamstring niggle, the Bangalore team may be in a spot of dilemma to get the balance right against Kolkata Knight.
With the trio of Chris Gayle, A B de Villiers and Tillakaratne Dilshan in blazing form, it would be a difficult proposition for the skipper to leave out any of the three in-form batsmen.
"Sometimes, you have to leave out somebody who deserves to be in the team to get the balance right. That's the hardest part. I think every captain in the IPL goes through that. You have so many good players and so many options," said Vettori.
"Our overseas players have performed exceptionally well. Particularly in the last few games, (Tillakaratne) Dilshan, (Chris) Gayle and AB (de Villiers) have done well and led us to victories. We know how important they are and we also know how important the Indian players are. It's difficult to get the balance. Every team goes through a bit of chopping and changing," he said.
Asked about the chances of Muralitharan playing tomorrow, the left-arm spinner said, "It's incredibly difficult as well. He is a good bowler. The games he played for us, he did a good job. We just continue trying to find the right balance. Guys understand that they might miss out in some games."
Vettori, who had to sit out in the rain-marred last match with Virat Kohli named as stand-in skipper said, "It was a precautionary measure. But I'm feeling good at the moment. I will have fitness test tonight. I'm pretty confident of playing tomorrow."
Vettori said he was happy with the performance of pace spearhead Zaheer Khan, who made a comeback in the IPL after an injury lay-off.
"I'm very happy the way Zaheer bowled. Particularly at the front and back end. He bowled well at the death in the last game against Rajasthan. I think we had the best bowling in our last game. That's encouraging.
"He is getting stronger and stronger. He is also a good leader with the bowl, particularly with the young Indian bowlers like Harshal Patel and R Vinay Kumar. So it's been a real help for me."
Asked about explosive West Indian batsman Gayle, who seems to be in blazing form this season, Vettori said, "He is a quality player. He knows his game inside out. Hopefully we can give him the confidence and freedom to go at it."
"Chris likes to play the way he wants. We can understand he likes to get himself in for five-six balls. Once he is settled, he is prepared to attack. He did that last year."
The skipper said Kohli's poor run with the bat so far in the tournament is not a cause of concern.
"He might not have got the runs the way he would have liked but he played well. He is a contributor. He gives everything on the field. He takes great catches. He tries hard and we know a good innings is not far away. These thing happens for any quality players. But I'm sure he would be back."
Asked about the Eden strip, he said, "Probably it would behave the way we have seen it -- reasonably slow and would turn a little bit. It's not the easiest thing for the batsmen and you have to adjust. Any team that hopes to win the IPL has to do well in all conditions."