Andy Murray remains convinced he can still challenge at the grand slams despite suffering his earliest Wimbledon exit.
However, the former world number one admits his injury problems since coming back from career-saving hip surgery mean he cannot offer any guarantees that he will be back for another crack next year.
However, 35-year-old Murray insists he still has what it takes to mix it with the elite at the major tournaments, fitness permitting.
“Has my opinion changed based on tonight’s match? No,” said the Scot.
“I think most of the players on the tour would tell you that a match like that was won or lost based on a few points here and there. I didn’t play well enough on those points tonight.
“I certainly didn’t serve well enough at the beginning of the match, which I think is understandable. Look, he’s a difficult opponent to play against.
“Tonight’s match, I don’t see why it should change that view really.”
Murray, who made his Wimbledon debut in 2005, wants to return to the scene of his greatest triumphs next year.
But he added: “It depends on how I am physically. If physically I feel good, then we’ll try to keep playing.
“But it’s extremely difficult with the problems I’ve had with my body in the last few years to make long-term predictions about how I’m going to be even in a few weeks’ time, never mind in a year’s time.
“If physically I’m in a good place, yeah, I will continue to play. But it’s not easy to keep my body in optimal condition to compete at the highest level.”
Isner’s 6-4 7-6 (4) 6-7 (3) 6-4 win was a first career victory over Murray at the ninth time of asking.
The 6ft 10in missile launcher sent down 36 aces while Murray managed just 15 points against his relentless first serve.
Murray’s preparation for the Championships was hindered by an abdominal injury suffered in Stuttgart a fortnight earlier.
He said: “It was frustrating, and it didn’t help. I was in a really good place physically and my game was in a good spot.
“The serve and return are the two most important shots in the game and I was not able to serve for essentially 10 days off the back of Stuttgart.
“The positive is that physically I was fine during the matches. It was touch and go, kind of, on the Wednesday or Thursday before the tournament in terms of how I was going to be.
“But I felt good physically on the court. I just couldn’t quite get the win today.”