Portsmouth have been in brilliant form over the opening 19 games of the League One season and have put themselves in a very strong position to win promotion.

Kenny Jackett's side currently sit at the top of the table, a whole four points clear of second-placed Sunderland and six points ahead of Luton Town in third-place.

The South-Coast side finished narrowly outside the top-six last season after winning promotion from League Two in the campaign before.

They have pushed on impressively, but they could soon lose one of their most important players.

Midfielder Ben Thompson moved to Fratton Park on loan from Millwall in the summer, becoming an integral presence in the centre of the pitch.

His partnership in the defensive midfield area with fellow summer-signing Tom Naylor has been integral to the club's success, allowing the attacking players in the side to express themselves.

But it now looks like Neil Harris will bring him back to the Den.

He is someone who will need replacing if he were to leave, and here are four players they could turn to...

Charlton are pushing up the table as well, but their constant instability leaves them vulnerable to losing their stars.

Aribo has proven to be an impressive presence in the Addicks midfield and would be the perfect replacement for Thompson.

With his contract expiring in June it is definitely on the cards.

Whiteman has been a crucial presence in the Doncaster midfield.

If Thompson were to leave, bringing someone in with the experience of playing in the upper echelons of the third tier would certainly be useful.

Longstaff recently signed a new-deal with parent club Newcastle United, but the Magpies could now be looking to send him out on loan to gain experience.

He would be a good short-term solution to the problem left by Thompson's departure.

Dobson has proven to be somewhat of a revelation under Dean Keates at Walsall.

The midfielder was made captain of the Saddlers' side last weekend and his combative nature in midfield would ease the loss of Thompson significantly.