Andy Irving and Elliott Frear scored in the first half, Kevin Cawley struck late for Alloa but Josh Ginnelly secured Hearts’ victory. Lacking match fitness, Mackay-Steven took up position on the right flank after replacing Jordan Roberts at half-time.
It was the new signing’s first action in exactly a month. His final outing for New York City on December 16 was a CONCACAF Champions League tie against Tigres in Mexico.
His initial few touches back home were purely about settling into the game. Whenever defensive or midfield colleagues took possession, Mackay-Steven would make a short dart towards them before a swift turn to sprint in behind the diligent Alloa left-back Lucas Williamson.
His first meaningful gallop was on a 56th-minute counter-attack. Craig Gordon, the Hearts goalkeeper, caught a corner and threw it out to Mackay-Steven in space, temporarily on the left. He sprinted around 70 yards at pace but the move petered out after a cross.
A rolled cross into the path of fellow substitute Liam Boyce should have been converted, and a similar delivery moments later evaded his team-mates. The final stages saw Williamson red-carded for a second caution after fouling Mackay-Steven.
Overall, Hearts’ new recruit showed potential to create chances and excite the Tynecastle support. However, the main objective for the visitors in Clackmannanshire was three points after losing here in November.
They handed rare starts to forwards Roberts, Frear and Euan Henderson. The hosts wanted to use the talismanic qualities of former Livingston midfielder Stefan Scougall to produce another shock.
Craig Halkett headed Michael Smith’s right-sided cross narrowly wide on 20 minutes as Hearts pushed for a breakthrough. Henderson then forced a low save from the Alloa goalkeeper Neil Parry after a precise through pass from Andy Halliday.
Irving opened the scoring in blistering fashion on 35 minutes. Retrieving a corner punched clear by Parry, he sidestepped an opponent and dispatched an unstoppable left-footed shot into the net from 20 yards.
The second arrived right on half-time when Roberts fed Jamie Walker on the right for a cross to the back post. Frear slid in to volley home from close range and accord his team a useful 2-0 interval lead.
Mackay-Steven appeared for the second 45 minutes and was soon followed by Boyce. Then came the long-awaited return of Ginnelly from injury as Frear made way.
Hearts now had what some would consider their strongest front three in unison – Mackay-Steven on the right flank, Boyce at centre-forward and Ginnelly on the left.
Within moments, they were carving Alloa apart. Walker’s side-foot volley from Halliday’s loping pass was just off target, as was Ginnelly’s right-footed drive before another Walker effort hit the side netting.
Williamson was dismissed before ten-man Alloa reduced the deficit through Kevin Cawley’s back-post header. Ginnelly struck minutes later on a lightning break to remove any doubt about the end result – and increase Hearts’ lead at the top.
Alloa (4-2-3-1): Parry; Robertson, Graham, Jamieson, Williamson; Grant, Hetherington; Cawley, Scougall (Buchanan 67), Murray (Brown 63); Thomson (Evans 82).
Hearts (4-3-3): Gordon; M Smith, Halkett, Berra, Kingsley; Walker, Irving, Halliday; Henderson (Boyce 59), Roberts (Mackay-Steven 46), Frear (Ginnelly 65).