The Middlesbrough skipper has struggled to complete a full training schedule in the last two months as a combination of knee and thigh injuries have hampered his start to the campaign.
O'Neil missed the second half of Boro's pre-season schedule, and the opening four matches of the season, after a niggling knee problem failed to clear up.
He then sustained a thigh injury in the last-gasp win over Burnley, and while he has been involved in three of the four matches since, he admits his fitness levels have not been as high as he would have liked.
The next two weeks will be spent improving his core fitness, and with Barry Robson and Kevin Thomson both set to be on the sidelines when Leeds visit the Riverside on October 16, O'Neil is determined to put a difficult two months behind him.
"It's been a really tough spell," said the midfielder. It's just been one thing after the other, and to be honest I can't really remember a worse summer and start to the season in the whole of my career. "It's been nothing major, but there have been so many little things that I've never really felt fully fit.
"It's hard to get over that because you tend to just go from game to game and you never really get a chance to properly put things right.
"That's why this break is going to be an important period for me. It gives me a chance to get out on the training ground and not have to worry about keeping myself right for a game in a couple of days time.
"I need that bit of time, and hopefully I'll be feeling the benefit when we all return to action in a couple of weeks."
Source: Northern Echo
Source: Northern Echo