By Gabriel TanFollow @@gabetan13
The Stags finish off their continental campaign at the Jalan Besar Stadium on Tuesday already in the knowledge that, with just two points from five Group H games, they cannot qualify for the Round of 16.
In stark contrast to their disappointing AFC Cup form, Tampines have been firing on all cylinders in the Great Eastern-YEO's S.League and currently hold a five-point lead at the top of the table after winning eight of their opening nine games.
Nonetheless, with a spot in the last 16 of the AFC Cup now beyond them, Mustafic is hoping his side can play to their full capabilities without any worries.
"I think there has been pressure in every game we've played so far," he said. "In the league, everyone is after us.
"It's not longer about who's going to win, but it's just teams wanting to beat Tampines. But tomorrow [Tuesday] there will be no pressure; we can really enjoy the game and go all out.
"We'll be playing for pride and for the club. We'll go all out, play entertaining football and try to win."
Malaysia Super League giants Selangor will definitely be up for Tuesday's clash given they can still book a spot in the Round of 16 if they pick up all three points at the Jalan Besar Stadium and Saigon Xuan Thanh lose to East Bengal in the other Group H match.
However, the Singapore international believes Tampines will have plenty to be motivated about, especially given the longstanding rivalry between Singapore and Malaysia.
"We're definitely motivated for tomorrow [Tuesday's] game," Mustafic added. "We're all disappointed with the AFC Cup campaign, especially since we came so close to winning in almost all the games.
"There is definitely this rivalry between Singapore and Malaysia to think about and we're ready to finish with a win and maintain our winning mentality. This has importance give it leads into Sunday's game [their league clash with Tanjong Pagar United.
"As a player you always want to give your best, especially in this kind of games. We may be disappointed but we are looking forward to tomorrow's [Tuesday's] game and are looking to win at least once in this competition."
One area where Tampines have had no problems in so far this season has been in attack, having netted 30 goals in 14 games in all competition.
In fact, they are actually the top-scoring side in Group H but have paid for their inability to keep them out at the other end but Selangor captain Asraruddin Putra Omar believes he and his defensive colleagues have what it takes to keep the Stags at bay.
"I'm confident in my ability and that of my friends," he said. "Of course, we drew with Tampines 3-3 [in their earlier meeting] and we know they have good strikers.
"But we have Peter Chrappan and good defenders on the left and right, like Mahalli [Jasuli]. I think we can stop them from scoring."
The Red Giants backline has been shuffled plenty of times so far this season after initial first-choice centre-back Ramez Dayoub was banned for alleged match-fixing and replaced by Chrappan.
Nonetheless, the Slovak has since been replaced in the side by Australian Adam Griffiths, although the latter's ineligiblity to take part on the tournament means Chrappan will return to the starting XI on Tuesday to play what coach Irfan Bakti hinted could be his "last game for the team".
Still, Asraruddin does not believe this chopping and changing will have too much of a negative factor on Selangor given how well they have prepared in training.
"I don't think there's any problem as we have trained with several different variations of defenders before," the 25-year-old added.
"In training, the coach always changes around the defenders to see how different things could work out."
Mustafic and Asraruddin have locked horns on several occasions in the past given both have been regulars for Singapore and Malaysia respectively in recent years.