Burnley manager Sean Dyche was disappointed to hear Chris Wood and Charlie Taylor "get slaughtered" by their former fans during Tuesday's Carabao Cup defeat to Leeds.
The Premier League side are also seeking a response from bookmakers Ladbrokes - the club's "official UK betting partner" - to a message on social media which contained a rude gesture towards the pair.
Dyche brought Wood and Taylor from Elland Road to Turf Moor this summer and the third-round draw gave them an early reunion with their old side, as well as a vociferous group of supporters who barracked them from the first whistle.
Wood scored twice from the penalty spot after coming off the bench, once in normal time to help force a 2-2 draw and again in a shootout which the Clarets lost 5-3.
Neither he nor Taylor would have expected a warm reception from the away end, despite their respective efforts across the Pennines over several years, but Dyche found the vitriol hard to comprehend.
"It's a strange business, football," Dyche said.
"Twenty-odd million they've made for a club (in transfer fees) and they get slaughtered. I don't know any more how fans react to players, ex-players, all that stuff, but that's football now.
"Those two have been fantastic servants to Leeds, if I'm honest. But Woody has done fantastically, walking on to our pitch and scoring, and again in the shootout."
Ladbrokes, who sponsor the Cricket Field Stand at Turf Moor, posted a message on their official Twitter account which was addressed to Wood and Taylor, followed by an image of a raised middle finger and the words: "Yours sincerely, Leeds fans #LUFC."
A spokesman for Burnley told Press Association Sport: "The club are aware of the problem. We have contacted Ladbrokes and are awaiting a full response."
Burnley last appeared in the final 16 of the League Cup in 2014 but could easily have remained in the draw had they taken one of a handful of first-half chances which fell to Scott Arfield, Sam Vokes or Ashley Barnes.
Instead they had to scramble for extra-time, Wood and Robbie Brady levelling in a frantic final period after goals from Hadi Sacko and Pablo Hernandez.
"There's never a lack of will and demand from the group, my only gripe is the amount of opportunities we created," said Dyche.
"The game should have been done in 90 minutes. That is where we're still shifting forward, that final moment of real quality. When you look up the Premier League ladder they find that final moment."
Leeds boss Thomas Christiansen, whose side can now harbour hopes of a cup run to go with maintaining top spot in the Sky Bet Championship, reserved a special word of praise for his goalkeeper.
Andy Lonergan was making his second Leeds debut between the posts having re-signed for the club this year and marked the occasion with a match-winning penalty save from James Tarkowski - the only miss from nine attempts.
"Andy made an important save to put us in the next round," said the Dane.
"I have a very good goalkeeper there and he proved it. I was a little bit anxious to see him in action because he has had a very good attitude in training. My expectations of him were fulfilled."