Not for combat. For combat he can use his power if he isn't playing a weapon (which he does not start with in his deck) and then he can roll his dexterity instead of his strength. But it is just pure dexterity, not acrobatics. So its just d10. But he can play all the blessings he wants on his own combat check and recharge them instead of discarding them.
To add to that - the only skills you can automatically use for combat are strength or melee - so if he had a melee +2 instead of an acrobat +2, you could use that. Barring that, certain weapon cards will tell you to use a different skill - like ranged weapons will allow you to use dexterity or a ranged skill bonus (which unfortunately he doesn't have either). But other than a card or a power allowing you to use something else, you normally can only roll strength or melee. Sajan's power allows him to use dexterity but if it was going to give you the acrobatics bonus as well it would say so, as that's not an automatic combat skill.