It is crunch time in the season for Derby County as they search for a play-off spot.

A vital win on Tuesday night pushed the Rams back into the play-off places as they leapfrogged Millwall by triumphing 3-1 over automatic promotion hopefuls Cardiff City.

Even though Derby's primary focus will be on promotion and even though they do not know whether they will be playing Premier League or Championship football next season, there will undoubtedly be one eye on transfers as we go into the final stages of this campaign.

Gary Rowett will have drawn up a list of potential transfer targets and he would be considering moves for a number of players who are out of contract this summer.

There are lots of good players who could be available on a free transfer this summer.

Here are six soon-to-be free agents who Derby need to offer a contract for next season.

Derby could add Aron Gunnarsson to their squad.

The Iceland international is a leader and will always give his all, adding tenacity and steel to their midfield.

The 29-year-old also has a long throw, which could be a real attacking weapon for Rowett's side in the Premier League or in the Championship.

Another no nonsense midfielder option is James McArthur.

The Scotland international is attracting a lot of interest ahead of the summer window but Derby should put their name in the hat.

Currently at Crystal Palace, the 30-year-old is a reliable defensive midfielder who could add quality to Derby's midfield in either of the top two divisions.

James Morrison of West Brom is another midfielder that Derby could pursue.

The Scotland international's contract at the Hawthorns is up and they have an option to extend it by a further year.

But before the Baggies try to extend his deal, Derby should offer him a contract instead.

If Derby could snap Junior Hoilett up on a free transfer, it would be a real statement of intent.

The Canada international has been a revelation for Cardiff, scoring nine goals and adding 11 assists this season in their promotion bid.

The Bluebirds will surely offer the 27-year-old fresh terms but Derby should make him a cheeky offer too.

Abel Hernandez is a prolific striker at Championship level and he would be a good option on a free transfer in either the Premier League or the second tier for Derby.

The Uruguay international scored 20 goals in the Championship two years ago and this season, he returned from a long-term injury to notch eight goals in 10 games.

With Newcastle chasing the 27-year-old, Derby will have to move quickly to snap him up but a partnership with Matej Vydra up front would be fantastic.

If Derby could snap up Ki Sung-yeung on a free transfer, it would be a real marquee signing.

While he does not get as many plaudits as he ought to, the South Korea international is experienced at the top level and he creates things in midfield.

If Derby go up, they should definitely rival the likes of Everton and West Ham in the race to sign the 29-year-old.