Watford suffered a frustrating afternoon at Vicarage Road as they were held to a first home goalless draw of the season by relegation-threatened Coventry City.

The Hornets were not at their best but upped their game after the break and had the chances to make it ten points from the last 12.

Troy Deeney was unlucky to see a shot tipped onto the post by Joe Murphy and have another effort well saved by the keeper, while what looked to be a certain goal for John Eustace was superbly blocked.

However, the Sky Blues were not without opportunities of their own though, as they sought a first away victory of the season.

The Hornets twice had to clear off their own line, while Tomasz Kuszczak also made a couple of impressive saves in a game in which the performance of referee Colin Webster was one of the main talking points following a series of baffling and inconsistent decisions.

But neither side was able to make the breakthrough as the game ended in the same scoreline as the reverse match between the teams in August.

Sean Dyche made one change to the side that triumphed at Derby County last time out but it was a particularly significant one as Britt Assombalonga became the 50th Academy graduate to make his first-team debut since it opened its doors in its current form in 1998.

The 19-year-old, who was recalled from his loan spell at Braintree Town earlier this week, replaced Joe Garner, who dropped to a bench that also featured Mark Yeates after a three-game absence. The two players to miss out as a result were Prince Buaben and Marcello Trotta.

Coventry came into the game trying to end an unwanted record of being the only team in all four English divisions without an away win. Furthermore, Andy Thorn’s side had taken just three points from a possible 51 on their travels and scored only seven goals away from the Ricoh Arena, six fewer than the Championship’s next lowest away scorers, Bristol City.

The opening minutes were scrappy, with the visitors edging the territorial exchanges, but it was Watford who created the first chance in the sixth minute when Eustace, making the 300th first-team start of his career, dug out a good cross from the left byline and Sean Murray got up well at the far post but was unable to keep his header down.

Following a stoppage in play while Deeney received treatment after a collision, the Hornets began to up the ante, with just the final ball letting them down on occasions.

However, the hosts’ next effort came in the 14th minute when Alex Kacaniklic swung in their second corner of the match from the right and Assombalonga leapt impressively but headed over the top.

Watford continued to be the more composed and confident side but it was Coventry who had the ball in the net in the 25th minute when Clive Platt headed home from a corner but the referee had already blown for an infringement.

The Sky Blues then enjoyed a reasonable spell of possession, without offering too much of a threat, although Nyron Nosworthy was forced to head clear a dangerous free-kick around the half-hour mark.

However, the Hornets were nearly undone in the 35th minute when Gary McSheffrey got round the back of the defence and stood up a cross beyond the far post from the byline and Platt headed back across goal, only for Jonathan Hogg to clear off the line.

Watford emerged through that awkward spell though, and created their next chance in the 41st minute when Assombalonga laid the ball off to the supporting Lloyd Doyley, who played in a good cross from the right and Eustace got across the near post but his attempted flick went over.

Kuszczak had not been called upon to make a save in the first half but that changed in the fifth minute of injury time when he did very well to get down sharply to his right to keep out Oliver Norwood’s shot from the edge of the area and the keeper then reacted quickly to push the loose ball behind for a corner.

The Coventry midfielder had the first effort of the second half as well, but dragged this one harmlessly wide. But five minutes after the restart Watford looked destined to take the lead when Nathan Cameron made a hash of clearing a cross and the ball broke ideally for Eustace, who smashed it goalwards, only to see his shot strike the centre-half and bounce away for a corner.

Despite putting in plenty of effort, little came off for Assombalonga and it wasn’t really a surprise when he was replaced in the 61st minute, with Chris Iwelumo entering the fray.

The big striker gave the Hornets more of an edge up front but it was his forward partner who came within inches of giving his team the lead when, after seeing his first effort blocked, Deeney advanced to the edge of the 18-yard box before hitting a right-footed effort that was heading inside Murphy’s near post until the keeper got down to tip it onto the base of his right-hand upright.

Moments later though, Kuszczak was again called into action to push away a dangerous Gary McSheffrey free-kick from right on the edge of the area after Nosworthy had been booked for a challenge from behind.

For reasons seemingly only he was aware of, the referee decided to get both managers together for an impromptu conversation on the touchline before Coventry made their first change, with Cody McDonald replacing Alex Nimely.

But Watford were close to taking the lead again in the 75th minute when Deeney worked a give-and-go with Iwelumo before advancing on goal from the left side of the area and attempting to dink it past Murphy, only for the keeper to get a touch and divert the ball narrowly wide of the far post.

Murphy was at it again moments later to keep out a firmly struck right-footed effort from Eustace before Murray was booked for a foul.

Kacaniklic’s afternoon was ended by injury with ten minutes remaining and he was replaced by Yeates but the hosts survived another scare in the 82nd minute when Kuszczak raced from his line to try and deal with a through ball, only for McDonald to nick it past him and put it just wide of the far post.

The Vicarage Road faithful were given added heart by the fourth official signalling for six minutes of additional time but it was the visitors who again went close to taking the points when Nosworthy’s lapse let in McDonald, who was eased slightly wide by the central defender but still managed to lift the ball beyond Kuszczak. However, the keeper managed to get the slightest of touches on the ball and Adrian Mariappa superbly read the situation to get back behind his keeper and clear off the line.

There was still time for the Hornets to have one last effort when Yeates cut in on his right foot from the left side of the area but Murphy dropped to his knees to save and keep hold of the ball.

Watford: Kuszczak; Doyley, Nosworthy, Mariappa, Dickinson; Murray, Eustace, Hogg, Kacaniklic (Yeates 80); Assombalonga (Iwelumo 61), Deeney. Not used: Loach, Taylor and Garner.

Coventry City: Murphy; Clarke (Christie 86), Keogh, Cameron, Cranie; Deegan, Clingan, Norwood, McSheffrey; Platt, Nimely (McDonald 72). Not used: Hussey, Dunn and Thomas.

Bookings: Nosworthy for a foul (66); Murray for a foul (76); Deeney for a foul (90).

Attendance: 12,563.