McLaren haven't confirmed its driver line-up for next season yet, although it is expected that rookie Kevin Magnussen will stay on after performing admirably so far this season.
That leaves his current teammate, Jenson Button – who is out of contract at the end of the season, on the proverbial chopping block.
Earlier this season Dennis urged Button to "try harder", but the McLaren boss admitted that there is little more the drivers can do in an noncompetitive car.
"Anyone who has actually seen the TV interview in question will know that there was an element of humor in what I said," Dennis told the official Formula One website when asked about the above-mentioned Button plea.
"Having said that, did I also intend to give Jenson a bit of a wake-up call? Yes, I did. But I did it softly, not maliciously. Indeed, perhaps the efficacy of my strategy was confirmed by the fact that Jenson immediately reacted by achieving his best race result of the year.
"Anyway, to tackle the specificity of your question, yes, I'm satisfied with both Jenson and Kevin. They're both capable of winning Grands Prix in a competitive car – Jenson has proved that 15 times in his long Formula One career, and Kevin has already demonstrated abundant pace in his so-far-short Formula One career – but clearly we're not giving them a competitive car at the moment.
"Nonetheless, despite that, I want them to give their best – and, at the same time, be responsible enough to appreciate that McLaren will always make efforts to hire the best drivers available. If such opportunities arise, we'll appraise them; we always have and we always will. All great Formula One teams are the same in that regard. But we're not in a position to do that at the moment."
After months of speculation, Dennis admitted that McLaren are interested in signing a new driver, with Fernando Alonso and Sebastian Vettel widely linked with a move.
"As I say, we'll always look to employ the best drivers available – but they have to be available, don't they," he continued.
"Having said that, for the avoidance of doubt, Jenson and Kevin represent an excellent blend of capable experience and youthful promise, and we're very happy with both of them. The fact that we're keeping an eye on what a few other drivers are up to in no way contradicts that, because, as I say, if opportunities arise, we'll appraise them – we always have and we always will."