Nicholson is a wanted man
Left-back Nicholson, 29, was not included in the Gulls' squad for Saturday's 1-0 League Two defeat at Hereford United.
United manager Paul Buckle explained that he had omitted the transfer-listed former Notts County, Sheffield Wednesday, Scarborough and Forest Green Rovers player because of increasing interest in him.
"Two or three Conference clubs have come in for Kevin," said Buckle.
Mansfield Town and Stevenage Borough, who were the first club to inquire about Nicholson's availability, are among the suitors.
If Nicholson goes, he will follow promotion-winning defender Chris Todd (Newport County), midfielder Chris Hargreaves (Oxford) and striker Tim Sills (Stevenage) out of Plainmoor in recent weeks.
But Buckle is also hoping to make the forward signing that he couldn't complete in time before the January Transfer Window closed. From this week clubs are allowed to make loan deals again.
"I am hoping to add a bit more strength on the ball," said the Gulls' boss.
"We need to add one or two."
Last week chief executive Colin Lee stayed in the North Midlands, after Tuesday's 1-1 draw at Crewe, and had held talks with several clubs, players and agents about possible targets.
With Scott Rendell out with a broken arm, and Chris Zebroski and Elliot Benyon the only remaining fit strikers, the positional priority is clear.
United missed out on Crawley Town's Charles Ademeno, 21, by a few minutes before the January window shut.
But that deal is not dead by any means, and talks over the former Southend youngster continue.
United have also said that they are in the market for a midfield player, in the wake of ex-skipper Hargreaves' move to Oxford.
The squad at Hereford included their latest signing, former Leicester City left-back Lathaniel Rowe-Turner, 20.
But Rowe-Turner was an unused sub behind a starting XI which had an average of 22.
"We have to fight for our lives," admitted Buckle after a defeat which leaves United with only two points from their last seven league games.
They haven't won since they beat Hereford 1-0 at Plainmoor on Boxing Day.
United are still seven points clear of the relegation zone, after one-from-bottom Grimsby lost 1-0 at home to Notts County.
But bottom side Darlington pulled off a surprise 2-0 home win over promotion chasing Rotherham, and Cheltenham earned a 0-0 draw away to AFC Bournemouth (2nd). Fellow rivals in distress Lincoln and Macclesfield both lost.
United, who have played more games than most, have a clear week until mid-table Port Vale come to Plainmoor on Saturday.
But several other teams are in action tomorrow night.
Darlington entertain Lincoln in a key fixture, Cheltenham are at home to Burton and Macclesfield travel to Bury.
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