By Gabriel Tan
The Stags edged closer to the last four of the competition on Monday evening as they came from behind to beat Albirex at the Jurong East Stadium, after second-half goals from Jufri Taha and Ahmad Latiff cancelled out Yasuhiro Yamakoshi's stunning opener in the 22nd minute.
Nonetheless, despite having a one-goal lead to bring back to the Clementi Stadium for Friday's second leg, Tan insists his side cannot get ahead of themselves.
"This is only halftime," the former Singapore international said after the game. "There are still two halves left to play.
"We have to remain focused and try not to concede on Friday. We'll play our normal game and if we concentrate and work hard, I'm sure we'll get the goals we need."
Tan also hailed the impact Jamil Ali made, after the dimunitive winger came on as a first-half substitute for the ineffective Ahmed Fahmie and gave the Albirex defence a real headache with his pace and movement.
"Jamil is a quality player," he added. "He always gives us something extra in the final third.
"I originally felt we needed to be more defensive against Albirex, which is why I started Fahmie. I was hoping he would be able to give us something extra with his aggression.
"However, we were losing too many balls up front which is why I had no choice but to bring on Jamil after 30 minutes."
Albirex coach Koichi Sugiyama echoed his opposite number's sentiments when he emphasised there was still plenty to play for on Friday, and is confident can still get the result they need to progress to the semi-finals.
"The tie is not finished yet and we still have a second half to play," he said. "Of course we are confident we can get the result we need at the Clementi Stadium.
"We have to be at our best on Friday, we will have to get ready and focus, but our players are younger than the Tampines players and hopefully they can recover faster."
Sugiyama insisted that he felt his side had not done too much wrong on the night, although he hinted at being slightly unhappy with the performance of referee K. Kalimuthu, who awarded the Stags a penalty in the first half which Takuma Ito kept out with a flying save.
"Nothing much went wrong tonight [Monday] although we made some minor mistakes," he added. "We couldn't get our passing game going at certain points.
"There were some mistakes from the players, and maybe from the referee as well. Maybe."
The RHB Singapore Cup quarter-finals resume on Tuesday evening when Gombak United take on Hougang United at the Jurong West Stadium.