All square in Paisley
St Mirren and Dundee United had to settle for a share of the spoils after a goalless Clydesdale Bank Premier League draw in Paisley, in which John Rankin was sent off for the visitors two minutes from time.
The hosts, in their last game before taking on Hearts in the League Cup final, looked the likelier scorers in the first half with efforts from Steven Thompson and Esmael Goncalves, set up by Gary Teale.
United were livelier after the break with their two best chances of breaking the deadlock falling late on to substitute Michael Gardyne.
St Mirren manager Danny Lennon made five changes to his starting line-up - Thompson and Goncalves, who came on as substitutes in the midweek defeat at Dens Park, started along with Paul Dummett, John McGinn and Teale.
Lee Mair missed out through injury in the Paisley club's last match before their League Cup final appearance, while Dougie Imrie, Kenny McKean, Sam Parkin and Lewis Guy all dropped to the bench.
Rory Boulding was handed a debut for United as one of two changes from their cup derby win, starting alongside Ritchie Ryan, in place of Jon Daly and the benched Gardyne.
Both sides enjoyed plenty of possession in midfield but goal chances were at a premium in the opening stages, with Willo Flood's corner headed clear by Carey and a Goncalves cross at the other end claimed by visiting goalkeeper Radoslaw Cierzniak.
Thompson twice came close to an opener for St Mirren midway through the first half.
He first headed onto the roof of the net after good link play down the right by Teale and David van Zanten, then saw a shot from Teale's cross put out for a corner.
United were unable to produce a shot to test Samson and it was the hosts who looked likelier to break the deadlock in what was a goalless first half.
Paul McGowan tried a turn and shot from the left side of the box but it was easily deal with by the diving Cierzniak. Teale, who had sent in a series of well-worked crosses, then found Goncalves two minutes from the break but the forward's header was well off target.
United had an effort with a good turn and shot from Boulding, unleashed from the right corner of the penalty box which Samson stopped well.
St Mirren then broke forward from a United free-kick and Goncalves found Teale, whose effort from the wing was caught by Cierzniak.
The visitors made a purposeful start to the second half, Stuart Armstrong shooting too high from a Rankin pass, followed by moments later by Boulting putting a shot wide of the right-hand post.
St Mirren responded with Thompson and Goncalves both coming close to meeting a Teale cross, with substitute Jon Robertson ultimately putting the shot over the bar.
McGowan made a good run on the hour but when he was stopped by a line of defenders on the edge of the area, he passed to Goncalves but his shot went into the arms of Cierzniak.
Good running by Flood and Armstrong as the game entered its final quarter set up a chance for Barry Douglas, but after arriving at pace down the United left, his diagonal shot ran right across the face of goal and out to safety.
Gardyne, introduced as a substitute only three minutes earlier, had the visitors' best chance when he sent an effort narrowly wide of the left-hand upright on 70 minutes.
Carey's subsequent free-kick for St Mirren was on target but easy for the goalkeeper, while substitute Imrie saw an acute-angle effort from the byline near the left-hand post go agonisingly wide.
Substitute Gardyne came even closer with 10 minutes to go when he connected well with a Douglas corner from the right, but his close-range shot was bundled off the line at the goalpost by Samson - and then Armstrong headed over from Keith Watson's cross.
Rankin saw red two minutes from time for a foul on McGinn just outside the box. Carey curled the resultant free-kick over the bar.