The former Chelsea striker, who enjoyed a prolific season on loan with Saturday's opponents Birmingham in 2003-04, had a further stint cut short due to a serious knee injury and returned to Stamford Bridge last season.
On his return to fitness, Birmingham snapped up the 25-year-old on a permanent transfer during the close season, but it has taken a little while for the Finland international to regain his sharpness in front of goal after his lengthy spell on the sidelines.
"He is a big, big talent," said Teemu. "Of course, if you have had a big injury like he has it is not easy to come back, but I think he is getting fitter and fitter all the time.
"He getting back to doing what he does best and scoring goals.
"I have seen him in a few games and he is looking like the old Mikael now. When he is fit he is a very good player."
It is coming up for eight years since Forssell departed HJK Helsinki for Stamford Bridge as a young prospect - according to Teemu, creating a lot of interest in his homeland, where they tracked his progress in loan moves to Crystal Palace, Borussia Moenchengladbach and Birmingham.
"Yes, he scored a lot of goals at youth level for the national team and there was a lot of clubs wanting to sign him. He was a teen star in Finland, he joined Chelsea and people at home have always followed his career closely.
"He is now coming back to his best and it will be good for our national team. He will again score a lot of goals in this league," added Teemu, who suggests he is the man to steer him away from goal on Saturday.
"If I play I will take care of him - no worries!"
Teemu Tainio believes his national team colleague Mikael Forssell is getting back to his best after injury.