The final game of 2017 saw United suffer a home defeat.
Gary Madine scored the only goal of the game in the first half, despite the Blades creating a number of efforts.
In the middle of busy festive period, Baldock and Donaldson were given a break, dropping to the bench, with skipper Sharp and available again Fleck returning to the starting line-up.
A frantic opening 10 minutes was devoid of chances, with United unable to match the start of Boxing Day. Duffy was prominent early on for the Blades, and was involved a couple of times in the same move that saw Fleck volley over.
Bolton grabbed the lead on 21 minutes after creating a two-on-one situation down the left. Robinson provided the cross and MADINE escaped O'Connell to touch home from a couple of yards. Madine also thought he should have had a penalty moments later following a tussle with Carter-Vickers but the officials disagreed.
In a difficult start for the home side, Lundstram was forced to block a Le Fondre shot after another move down the left, Fleck picked up booking and Carter-Vickers was replaced by Baldock with Basham switching to a central defensive role.
Baldock was soon in the action, his shot was saved by Alnwick after Clarke's lay-off as the end of the half saw the Blades get on top. The best opportunity arrived on 43 minutes - simple forward passes from O'Connell and Duffy put Clarke through but his low effort was saved by the inside of goalkeeper Alnwick's leg.
United forced Bolton back at the start of the second half. There were calls for a penalty when Lundstram went down, ignored by the referee, and a Clarke looping header was easily collected by Alnwick.
Madine got the better of Basham but shot straight at Moore and United were quickly back on the attack with O'Connell heading wide a Duffy free-kick.
Donaldson was introduced for Sharp and United continued to put the visitors on the back-foot. Baldock found space on the right and saw his first shot blocked and second turned around a post by Alnwick.
The attack-minded Carruthers replaced defender Stearman as Wilder's last change. Baldock fired over after Bolton after cleared as the game approached the last 10 minutes.
On 82 minutes Fleck's pass found Donaldson but he could only shoot wide after the ball dropped over a defender's shoulder and the late pressure was coming from the Blades.
Six minutes of added time offered hope and the best chance of note arrived three minutes in as Baldock got around the back of the defence but his pass was just behind Clarke, who could only divert the ball over. Baldock had an effort blocked and Carruthers fired wide late on.
A disappointing end to a glorious year.
Blades: Moore, Stevens, Fleck, O'Connell, Basham, Lundstram, Clarke, Sharp (Donaldson 61), Carter-Vickers (Baldock 31), Stearman (Carruthers 79), Duffy.
Unused: Wright, Lavery, Lafferty, Blackman.
Bolton: Alnwick, Beevers, Le Fondre (Armstrong 75), Madine, Robinson, Cullen (Vela 82), Pratley, Morais (Little 64), Henry, Wheater, Burke.
Unused: Buckley, Osede, Wilbraham, Turner.