Samuel Eto'o scored a hat-trick in a result which forced captain Nemanja Vidic, who was sent off late on, to concede that United's title defence is over with Arsenal, Manchester City and third-placed Chelsea 14, 13 and 12 points ahead, respectively.
"I don't think we're a long way away from the teams at the top," Jones told manutd.com.
"If Chelsea are one of the best two or three teams in the country, then I think you have to say we can be right up there alongside them - our performance in the first half proves that.
"We're not a million miles away, I'm telling you, but we need to stick together if we're going to turn it around."
Jones admitted United's defeat at Stamford Bridge came down to being unable to take their chances and sloppy defending.
"We started really well," Jones said.
"I thought in the first 30 minutes we were terrific. We set out and started in exactly the way we spoke about beforehand.
"We took the game to Chelsea, they couldn't get out of their own half and we totally dominated the match from the first whistle.
"We just couldn't find the goal that we probably needed to kick on from there.
"Then they had a bit of luck for the first goal and we conceded a couple of sloppy ones.
"Conceding just before half-time never helps."
United will also bid to overturn a deficit in the Capital One Cup semi-final with Sunderland.
David Moyes' men trail 2-1 entering the second leg at Old Trafford and will be without Vidic, who will serve a three-match ban following his dismissal at Chelsea.
Jones added: "Now we have to bounce back and we have an important game on Wednesday night."