The 34-year-old all-rounder has been the outstanding performer for the club this season, following his switch from Middlesex and has turned in a succession of consistent displays with both bat and ball.
They are big boots to fill because he (Ervine) is a fantastic t20 playerGareth Berg
Although his team-mates have fired at times, they have been way down on their best in the Championship.
In contrast, the t20 campaign has produced five wins and three defeats so far and Hampshire remain on course for the a place in the quarter-finals once again.
But they will be missing a key cog in the wheel, with Ervine sidelined for the trip to Chelmsford with a fractured finger he picked up in the nine-wicket Championship thrashing by Somerset this week.
Berg made an impressive Hampshire t20 bow in the defeat to Sussex last week when he replaced Jackson Bird in the ranks.
But it could be a different role in the side for the South African tonight, with a reshuffle on the cards.
Berg said: ‘With Slug (Ervine) out, it will be pretty tough to fill that role because he has been fantastic.
‘There hasn’t been any chat about it yet, but if they need me to do it then I would put my hand up and take that role – definitely.
‘They are big boots to fill because he is a fantastic t20 player.
‘But the t20 has always been one of my favourite parts of the game, in terms of entertaining and that.
‘It’s quite a good format for me in terms of stats and I like to contribute.
‘It’s a tough crowd at Chelmsford and with those short, straight boundaries it’s a hard place to bowl.
‘But, hopefully, we will do well.’
Berg took one for 24 from his four overs and batted at number eight in the seven-wicket defeat to Sussex last week.
Ervine, meanwhile, usually bats at number five but has only been used on occasions with the ball.
It appears to be a straight choice between Liam Dawson and Jackson Bird over who comes into the side with a subtle change to the balance and a shuffle to the batting order.
Berg said: ‘I don’t mind batting at eight or nine or wherever they need me.
‘I’ve always backed myself to be a good cricketer in t20.
‘It’s about change-ups and bowling at the death, if needed.
‘I think I can hit a few at the end of an innings as well.
‘At the moment, I am striking the ball nicely and I’m in good form with the bat so we will see what happens.’
Hampshire appeared to be protecting Berg earlier in the tournament after he missed the whole of last season with a shoulder problem.
But after biding his time for his opportunity, the all-rounder has shown he is firing on all cylinders and believes he is in the form of his life.
‘I wouldn’t say I was frustrated to miss out on the t20,’ said Berg.
‘In many ways it was nice to be sitting out and letting the body relax before the next Championship game.
‘I’m glad I did pretty well in the first one I was involved with.
‘In terms of my whole career, I am probably at the best stage I have ever been, which is great – especially for my new team.’