Lewis Hamilton won his fifth world title last season, with Bottas ending down in fifth.
The Finn did not win a single race, finishing second on seven occasions.
But Bottas ended off the podium on too many occasions to challenge for the title, with Sebastian Vettel being Hamilton’s closest competitor.
Ferrari have had the better of the first few days of pre-season testing in Barcelona though Hamilton impressed still.
And the Brit knows Bottas can up his game with Mercedes this year.
“I’m not someone that generally has expectations of anything, but I would assume that he’s going to try and be more aggressive this year,” Hamilton said.
“I’m sure he’s going to be pushing harder, I’m sure he’s pushing harder on his training.
“He’s always been incredibly determined since the day he got here, and that’s not wavered.
“I’m sure he knows where he’s got to put his focuses to, working with his guys on the other side. I see the top of his head beyond the screen, so I don’t really know about his difference in approach, but I’ll see that once we get into the racing this season.
“Every teammate has different qualities, different way of approach, different values, and different work ethics.
“Ultimately I would say Valtteri has been probably the most all-rounded driver that I’ve worked with in that respect, and probably the most humble driver that I’ve worked with.”
Bottas had helped Hamilton on plenty of occasions last season.
During the Russian Grand Prix for example, Bottas was leading when told by Mercedes chief Toto Wolff to let Hamilton pass.
But the Finn thinks it will be fairer this year.
“I have no concerns, because we have agreed something already a couple of years back and it’s going to be up to my performance,” Bottas said via Crash.net.
“Obviously we’ll see how the season goes.
“Last year there was a big gap between Lewis and myself, then things were slightly different. It’s going to be up to me, so no concerns.”