The pint sized striker is a regular in Peter Taylor's team this seasona after a switch from Northampton Town just over a year ago.
The signing of Walters is likely to push the ex-Leeds man down the pecking order, sparking speculation that he is to return to Blundell Park.
Pearson denied Forrester was leaving, stating he's very much part of Taylor's plans.
Jamie isn't going anywhere. He's our player and that's how we want it to stay. He's still an important part of Peter's plans," he told the Hull Daily Mail.
"As for Grimsby, some people have looked at the situation and jumped to entirely the wrong conclusion. It's absolute nonsense."
Forrester first arrived at Blundell Park in the final few months of the 1994/95 season. Brian Laws brought him in from Leeds on a loan and despite an initial shaky start, Forrester was soon impressing.
Laws was keen to make the deal permanent in the summer but any deal fell through due to Leeds' high valuation.
The following March though Laws' persistance paid off as he got his man on a free transfer.
Forrester started 27 league games for Town with 14 sub apperances, notching up 6 goals before he moved onto local rivals Scunthorpe in March 1997.
Forrester made his name with the Iron and it earned him a move to Dutch outfit FC Utrecht. His spell on the continent didn't work out though, nor did the return to English football with Walsall.
Northampton proved more successful though. Over 100 games and exactly 50 games for the Cobblers, only finances saw his free transfer switch to the Tigers.
The move saw Forrester become one of very few players to have played for all three 'Humberside' clubs.