United's slim hope of sneaking into the play-off positions was ended in Saturday's penultimate encounter of the campaign.
Two early goals put the Blades on the back foot and despite Billy Sharp's 21st goal of the season, Nigel Adkins' side slipped to a first defeat in six.
Boss Adkins was forced into one change to his starting line-up - Whiteman replaced Hammond. Also, 17-year-old goalkeeper Ramsdale took over from Howard on a youthful bench. Hammond and Howard missed out as their respective partners were due to give birth.
There was a huge sign that it was not to be United's day when, with the first effort of the afternoon, Coventry took the lead with a goal off a player's backside! Armstrong cut in from the left channel and his shot took a huge deflection off FORTUNE's bottom, taking the ball away from an already-committed Long.
There was an immediate opportunity to draw level when Adams nipped in ahead of Vincelot and goalkeeper Charles-Cook but he dragged his subsequent effort wide. Coventry were more clinical with their next chance, doubling the lead. United half cleared a corner but Cole's ball found the run of ROSE, who clipped into the top corner as Long surged off his line.
After the initial shock of conceding a second, United looked to get back into the game. A quick free-kick between Basham and Baptiste saw Sharp get around the back of the defence but he stayed on his feet, despite a nudge from Stephens, and then, from a Whiteman cross, Adams forced a save out of Charles-Cook at the back post.
At the other end, Coventry had two efforts blocked and Armstrong got away from Baptiste and looked in the clear but the loan defender recovered.
After the half hour, Flynn's shot was pushed away by Charles-Cook and moments later Sharp drew the Coventry goalkeeper but his low cross was cleared by Sky Blue shirts.
Late in the half the majority of the attacking endeavour was coming from the Blades but the visitors were unable to reduce the arrears before the break as Basham failed to find the target with a back-post header.
An early Hunt cross and a long-range Fleck shot put the Blades on the back foot early in the second half, but United responded with a penalty appeal as Cole slid in and appeared to handle and an Adams shot which was held by Charles-Cook.
United were then handed a lifeline with a penalty on 58 minutes. Flynn and Adams were involved before Martin bundled over Sharp. SHARP took responsibility for the spot-kick and smashed past Charles-Cook to half the arrears.
As United searched for an equaliser, Coutts came to the fore. He had an effort blocked, took a free-kick which was eventually cleared and then fired over from 25 yards. Basham also curled wide, whilst Coventry's Cole went close.
Entering the final 15 minutes, the pressure was now all coming from United. Basham fired wide from 10 yards after Sharp's battling earned a chance and then there were a number of threats without clear-cut chances. On the break, a combination Done and Long kept out Jones, but when Done surrendered possession two minutes later it, Coventry had players over before LAMEIRAS fired home with Long exposed to put the game out of United's reach.
Teenager Kelly was introduced for his debut with a minute to go and in injury-time the early luck was repeated when an Edgar header was blocked by team-mate Adams from a Coutts corner.
Coventry: Charles-Cook, Vincelot, Fleck, Armstrong, Cole, Stephens, Rose (Phillips 69), Martin, Thomas (Jones 65), Fortune (Lameiras 76), Hunt.
Unused: Gadzhev, Tudgay, Harries, Addai.
Blades: Long, Basham, Flynn (Woolford 66), Coutts, Sharp, Done (Kelly 90), McEveley, Baptiste, Adams, Edgar, Whiteman (Reed 85).
Unused: Sammon, McGahey, Brooks, Ramsdale.