Dismal Huddersfield Town were undone by a couple of loan men, leaving fans debating whether Mark Robins should go into the market for a November tonic.

A worst defeat since March, when Robins’ side went down 4-1 at Brighton, and a heaviest at home since last December, when Simon Grayson’s side were beaten 4-2 by Leeds, reinforced two points.

Firstly that Town don’t have that much depth in their squad, and secondly, that they are too susceptible to set-pieces.

The second-half double by Swansea’s Kyle Bartley which clinched Lee Clark’s first win over his former employers in three attempts came from deliveries by Manchester United’s Jesse Lingard – the first a corner, the second a free-kick.

In the four games since the last international break, Town have lost three and conceded nine goals, six of them from set-pieces.

They clearly have to improve in that area, but must do so without centre-back Peter Clarke.

Early indications suggest the knee injury which forced him off six minutes into this match means he’s unlikely to be back this side of Christmas.

Town certainly missed their captain, just as they did midfielder Jonathan Hogg, kept out by the knee problem picked up during the 2-1 defeat at Wigan, and 11-goal top scorer James Vaughan, who completed a three-match suspension.

They should have Hogg and Vaughan, who contributes in defence as well as attack, back when action resumes at Sheffield Wednesday a week on Saturday, but the absence of Clarke is a concern, not least because Town only have Joel Lynch, Anthony Gerrard and Murray Wallace as their other specialists in the position.

While Gerrard returned after two games out – and grabbed the 31st-minute goal which provided home hope after the loss of Clarke and Nikola Zigic’s 11th-minute opener for Birmingham – Adam Clayton remains out of favour after that alleged training-ground bust-up with Martin Paterson, who is recovering from surgery on a hand.

Teenager Duane Holmes looks able to provide the forward runs from midfield that Clayton is capable of, but he is far from the finished article, and other factors prevented the American youngster’s introduction into Saturday’s showdown from the bench in any case.

Having already replaced Clarke with Joel Lynch, named as a substitute because a thumb operation had limited his ability to train, Town were trailing 2-1 when Robins brought on Oscar Gobern and Danny Carr for Ollie Norwood and Jon Stead after 64 minutes.

The pair had hardly sunk their studs into John Smith’s Stadium turf when Bartley notched his first of the game.

Town tried to force a second equaliser, but were far from convincing, and their task became even harder when Bartley bagged his second.

The already-cautioned centre-back’s celebrations weren’t to the liking of referee Gavin Ward, who brandished another yellow then red, but Birmingham, for whom former Town striker Lee Novak had a lively game, held out comfortably enough for their first win in five.

Abject: Huddersfield Town boss sums up performance in Birmingham City defeat

Run of the ball

2mins:  Former Town striker Lee Novak’s low shot is palmed clear by Alex Smithies.

11mins:  GOAL to Birmingham. Novak’s flick from Mitch Hancox’s cross is parried by Smithies, leaving Serbian striker Nikola Zigic a straightforward finish from close range.

20mins:  Jon Stead heads over from Paul Dixon’s cross.

24mins:  Neat play by Sean Scannell brings a free-kick on the edge of the penalty box, but Danny Ward’s well-struck effort is diverted for a corner.

25mins:  Birmingham’s Jesse Lingard walks the ball home, but Zigic, who played him in, is adjudged to have been offside.

31mins:  EQUALISER for Town. Paul Dixon pushes forward and wins a free-kick, which Adam Hammill flights in for Anthony Gerrard to net with a glancing header.

33mins:  Callum Reilly’s shot is saved by Smithies.

38mins:  Novak’s shot is held.

40mins:  Scannell has a low shot saved.

55mins:  Smithies stops Novak’s piledriver.

55mins:  As play swings to the other end, Hammill puts an angled effort across the face of goal.

66mins:  GOAL to Birmingham. Lingard’s corner is headed home by Kyle Bartley.

78mins:  Ward puts a low drive just wide.

81mins:  GOAL to Birmingham. Bartley nets again with another header from another Lingard delivery, this time a free-kick.