Rangers clinched their place in the Betfred Cup semi-finals with a comfortable 4-0 win over Ayr United – but now face a Hampden dilemma after frontman Alfredo Morelos picked up a booking that will rule him out.

Gers' top scorer netted the third goal against the Ladbrokes Championship leaders as the Light Blues strolled into the last four.

But another petulant outburst at referee Bobby Madden earned him his second caution of the competition, leaving Steven Gerrard with a major headache ahead of their semi showdown.

With Kyle Lafferty cup-tied, the Ibrox boss will have to come up with a new solution.

Teenager Glenn Middleton, however, showed he might just be the man to spearhead Gers' attack at the national stadium with a well-taken brace on his full debut in the first-team.

Gerrard made six changes to the side that dismantled St Johnstone on Sunday but they showed no sign of disruption after Nikola Katic nodded them ahead early.

Ian McCall's Honest Men took the lead when the sides met in a William Hill Scottish Cup tie last season – and came close to a repeat 10 minutes in when Robbie Crawford's long-range strike forced Wes Foderingham into an impressive finger-tip save.

Gers went on to canter to a 6-1 victory at Somerset in that February clash and again they proved too strong.

Middleton's first real involvement came after 17 minutes as the youngster whipped in a vicious low cross, forcing Mike Rose to put behind for a corner. Ryan Kent took over the delivery duties and picked out Katic to head home.

Ayr found themselves undone again on 31 minutes as Andy Halliday's beautiful lofted pass caught the Somerset defence napping, with Middleton darting in off his wing to slam past Doohan.

But then came Morelos' latest meltdown. The Colombian was sent-off against Ufa last month after aiming a blast at the referee and despite being warned by Gerrard to clean up his act, he let fly with another tirade at Madden after being caught late by Jamie Adams.

If the realisation that he had let his team down again affected him, he did well to disguise it as he put the tie to bed four minutes into the second period.

As a Middleton corner was flicked towards the 22-year-old in the six-yard box, he still had work to do with Rose looking to get tight but Morelos refused to be shaken off and hooked home with his right foot.

Gerrard wasted no time in whipping the striker off and replacing him with Eros Grezda as he gave Kent the chance to show if he could lead the attack.

Jordan Rossiter was also given a cheer as he made his latest comeback from injury with youngster Stephen Kelly also introduced for his debut.

But it was winger Middleton who again stood out, spinning away from Rose as he collected another Halliday pass before rifling beyond Ross Doohan as he completed the scoring with 20 minutes left.