Welsh international Joe Morrell and Ryan Tunnicliffe are the duo under contract going into the 2022-23 campaign.
However, Louis Thompson, who has impressed at the back end of this season, is expected to have his option triggered come the end of term.
The same can’t be said for 35-year-old Shaun Williams, though, who looks likely to depart Fratton Park after just one year.
The Blues have already been linked with a move for Accrington man Matt Butcher prior to the window opening as Cowley scouts for potential new options.
But we’ve taken to WhoScored.com to find out who the best performing free-agent midfielders from League One and League Two are this season and who the Blues might be interested in.
Here’s what we found.
1. Adam May
Club: Cambridge United; Age: 24; Appearances: 36; Goals: 5; Assists: 3; WhoScored rating: 6.83. Photo: PAUL ELLIS
2. Sam Hutchinson
Club: Sheffield Wednesday; Age: 32; Appearances: 25; Goals: 1; Assists: 1; WhoScored rating: 6.88 Photo: Jacques Feeney
3. Louis Reed
Club: Swindon; Age: 24; Appearances: 36; Goals: 1; Assists: 3; WhoScored rating: 6.9 Photo: Pete Norton
4. Conor McGrandles
Club: Lincoln City; Age: 26; Appearances: 38; Goals: 2; Assists: 1; WhoScored rating: 6.91 Photo: Mike Hewitt