Within six months of taking charge at Tannadice, McLean has put Dundee United, who edged back into the Premiership last May via a play-off, two steps from a repeat of their 1994 Cup success. Two goals from Andy McLaren and one each from Robbie Winters and Kjell Olofsson put paid to Motherwell, who replied through Mitchell Van Der Gaag.
After a goalless first half, their place in tomorrow's draw alongside the favourites, Celtic, did not look in doubt once McLaren had put them ahead in the 47th minute. By the end, the only pressure on McLean, who this week collected his third successive manager of the month award, was coming from the home fans. He satisfied them with a presidential wave.
United had started in such electrifying fashion that none would have expected the blank half-time score. Within the first 10 minutes, Ray McKinnon (twice) and McLaren let chances go to waste before a flurry of three yellow cards broke the flow of the game.
Motherwell began to show as an attacking force in the last 15 minutes of the half only to fall behind after the restart. McKinnon released Olofsson and the Swede drew two defenders before setting up McLaren. The second arrived in the 62nd minute when Winters finished a flowing break by diving to head in Steven Pressley's cross, and three minutes later, nightmarish Motherwell defending left McLaren with an open goal.
Although Mitchell Van Der Gaag pulled one back for Motherwell with 11 minutes left, United had the last word as Olofsson rewarded for a tiring supporting run with a tap-in after Scott Howie had palmed out a shot from Winters.