But the good news is that captain Jack Edwards, midfield colleague Devon Kelly-Evans, Dan Turner and Dan Meredith are among the first confirmed to be staying.
Both departing players made 44 appearances for Brakes last season and were key members of Paul Holleran’s squad ensuring a sixth consecutive season of Step 2 football.
Gittings arrived at the club in March 2016, initially on loan, and has since made 220 appearances, scoring 11 goals.
He has been popular with supporters for his feisty performances in the centre of the park as well as his occasional his stints in goal.
Holleran said: “We're disappointed to see him leave us after so long, but Callum is 36 now and with a young family he is going to take some time to decide whether to play on for another season.
“We knew it was probably going to be his last season in the National League North and if he does continue it will probably be at Step 3 where there is less commitment and less travelling.
“Callum has been a big part of our squad over several seasons and his experience has played a huge part in stabilising the club in the National League. It was a great way for him to finish with us, getting goal of the season against Kidderminster, one of his former clubs, and then obviously being a big part of the team that won the Birmingham Senior Cup at the Aston Villa, the club he supports.
“In my time as manager here he is right up there as one of the best players I have ever managed. It's a sad day, but sometimes these days are inevitable.”
Gittings added: “It was a tough call but I think it was the right time. I've had a fantastic six years here and it's been a privilege to play for Leamington. I'll take away some great memories and have met some great people along the way. It wasn't a bad way to finish, with that goal and to win the cup at Villa Park!”
Parker made 54 appearances, scoring four goals since arriving from hometown club Gloucester City early in 2020. His job is taking him further south so the commute to Leamington is no longer viable.
Holleran added: 'We're bitterly disappointed to lose both players but sadly that's part and parcel of football. I think I speak on behalf of everyone when I say it's been a pleasure with both of them.”