The Dutchman doesn't believe that he is realistically in a battle with race leader Chris Froome (Team Sky), despite gaining 27 seconds on him during Wednesday's summit finish on Los Machucos.
The margins are small in the fight for the final podium place, but Kelderman held onto the third place he reclaimed in Tuesday's time trial, with just 12 seconds separating himself and Zakarin. He is now 57 seconds behind Nibali, who is in second place at 1:16 behind Froome.
"I see Nibali and Zakarin more as my rivals than Froome," Kelderman said after the stage.
The brutal ascent of Los Machucos destroyed the Vuelta a Espana peloton as expected and had riders scattered down the mountainside. While Alberto Contador (Trek-Segafredo) attacked with Miguel Angel Lopez (Astana) in the lower slopes and Froome struggled, Kelderman stuck with the main group of contenders for much of the ascent. There was little thought about how much time he was gaining or losing. It was all about getting to the top as quickly as he could, and he would assess the damage later.
"I didn't know that Froome was behind and Contador was ahead because, on a climb like this, you're not getting any information. It's just riding full gas," he explained.
Aside from the early jaunts by Contador and Lopez, the final ascent was more attritional than aggressive. Kelderman could see the merit in the spectacle, but he wasn't in a hurry to be doing it again – although he will have to with the Alto de Angliru to come at the weekend.
"This is not my favourite climb, but it went very well," said Kelderman. "It was very steep and undulating so you can't really get your rhythm, you're just fighting all the way up. Personally, I don't like this, everybody just riding by themselves instead of attacking from the group. It is fun for one time because the fans and the media like it."
The stage ultimately ended up being about damage limitation for Kelderman, but he was able to take some positives out of it. There are two medium mountain stages to come over the next couple of days before the Angliru on Saturday, and Kelderman remains hopeful about his chances.
"On a climb like this, you can't think, you just go," he said. "But my legs are feeling pretty good, and hopefully in the next couple of days everything goes well."