Benjamin Mora commended the efforts of his players, despite seeing Johor Darul Ta'zim (JDT) crash out of the AFC Cup in agonising fashion after losing 2-1 to Ceres-Negros in the Philippines.
In the second leg, JDT conceded an added-time penalty from Fernando Rodriguez to lose on away goals after a 4-4 draw on aggregate in their ASEAN zone semifinal.
Ceres will play Singapore's Home United in the ASEAN zone final over two legs in August.
To top off a miserable night, Malaysian giants JDT saw their goalkeeper Farizal Marlias sent off for pushing the referee out of frustration after the Ceres penalty.
"When you lose like this for any reason at all, it hurts a lot," said Mora.
"We invested a lot in this team, our owner (TMJ) has invested a lot of time to fight in this competition. We came to fight like warriors with our chest lifted and our chest pumped up. So it is sad that we have to go out like this."
In front of a capacity crowd at Panaad Stadium, Ceres captain Kota Kawase gave the hosts a 26th-minute lead and advantage on aggregate, due to away goals.
But Gabriel Guerra swung the tie back in JDT's favour with a well-taken goal midway through the second half, which seemed likely to put the Southern Tigers through.
That was until Aidil Zafuan, under pressure from a corner in the dying minutes, barged into Manuel Herrera, which made the Chinese referee point to the spot.
"It was a penalty because the referee said it was a penalty. We tried to play the better football, but so did Ceres who are also a good side. The AFC Cup is a respectable competition for JDT, and we always want to compete and fight," Mora added.
JDT boss TMJ also rallied behind his players after the loss.
"This club and players are in my blood, I will not trade them for anything else," said TMJ, who also backed Farizal for his actions in a video posting.
"Farizal Marlias, I'm with you."
JDT also fell in the semifinals of the 2016 edition after a 4-2 aggregate loss to Indian side Bengaluru FC.
The Southern Tigers' local players will now report for national centralised training at the Padang Gelam facility in Johor Bahru on Friday.
Eleven JDT players, including the comeback quartet of Safiq Rahim, Amirulhadi Zainal, S. Kunanlan and Aidil, were included in Nelo's Vingada's squad to face Lebanon in the AFC Asian Cup qualifiers on June 13.