But the Potters still kept a fourth consecutive clean sheet and with Joe Allen returning off the bench after nine months out with an Achilles injury, O'Neill believes his options are growing.

He said: "We haven't been able to rotate the team as much as we would like because of the players that have been out, and we probably have the opportunity now which will keep us a little bit fresher.

"It was great to see Joe back. We've had to hold him back a bit but it's a real positive for the group.

"We are getting players back now – John Obi Mikel and Sam Clucas, for example, are coming back into contention and I believe we will be stronger in the second half of the season.

"We've got a lot to play for and these players will help us. There's no doubt we need more goals to come from the team, we lost a big threat with Tyrese Campbell coming out injured.

"I thought we were dominant in the second half in particular and had enough chances to win the game but unfortunately we couldn't take them.

"The most important thing is that we creating chances but, yes, it would be nice to see some of those chances go in. There were one or two that we should have done better with.

"When you look at the teams occupying the automatic promotion places, we still have a way to go to compete with them but we are going in the right direction."

For Coventry, the return of last season's leading marksman Matty Godden from a foot problem was tempered by the absence of strike partner Tyler Walker, who will miss six weeks with a calf injury.

Potters keeper Joe Bursik saved from Godden and Callum O'Hare as Coventry, seven points above trouble in 18th, were held to a third straight 0-0 draw at St Andrew's.

Boss Mark Robins said: "To get 70 minutes from Godden was magnificent, it was great to get him anywhere near the team at this stage which is testament to how hard he's worked.

"It's a good point against really strong opposition – you look at their bench and it's frightening.

"For the first hour, we probably had the better opportunities of the two teams. I thought we moved the ball really well but we sometimes had one pass too many where we could have taken a shot.

"If we had taken those opportunities to shoot a bit earlier, we may have had a bit more joy.

"You could probably write the script before the game because they are probably the best-drilled defensive team in the division.

"It was really tight, nip and tuck all afternoon and probably a fair result at the end of it. A clean sheet and another point, it's a really good point."