Allardyce was never in doubt West Ham would soon get the best out of veteran goalkeeper Jaaskelainen once again.
"The big man is there to do a job and he has done the job superbly well for us," the West Ham boss said.
"I know that Jussi's strength was the coaching that Fred Barber used to give him at Bolton, which he lost.
"I knew that when he got with here with Martyn Margetson, that Marge would sort him out, put him back into a right good frame of mind and rekindle all the old experience he used to have.
"Perhaps he had lost faith in himself a little bit and lost faith because he wasn't playing, but Marge has rekindled his confidence and put him in the right frame of mind."