The 30-year-old Croatia international spent the whole of the season just ended on loan with the Trotters from French club Nantes and Davies was impressed with the improvement Klasnic made during the campaign.
He told the Bolton News:“He’s taken the manager’s information on board and is working harder and his stats will back that up.
“I always look at them on a Monday morning after a game and see how hard I’ve worked and you have a quick look at the other players – his stats have been higher in the last two or three games.
“It’s something he realises he has to add to his game if he wants to stay and he has done.
“Ivan’s dangerous inside the box and always looks to turn and get a shot off. He’s one of the best I’ve ever worked with at that and will never turn down a shot.
“He’s a goalscorer and a good lad to have in the changing room.”