Although not told he is unwanted at St Mary's, Sharp's name does not appear to be high on manager Mauricio Pochettino's list of priorities.
The 27-year-old was overlooked for the club's pre-season trips to Spain and Austria, when the first of the first-team squad travelled.
Sharp helped the Saints to the Premier League in 2012 but was loaned out to Nottingham Forest last season, with Pochettino opting against recalling him when he replaced Nigel Adkins in January.
And Sharp's agent, James Featherstone, seems to accept his client's days at the club appear numbered.
"It is a bit of a difficult one at the minute," Featherstone told Press Association Sport.
"He has been pre-season training with Southampton, working hard, and obviously he wants to try to force his way into the team.
"With him being out on loan last season and a new manager coming in, he hasn't really had a chance to impress.
"He wants to play football, he doesn't just want to sit out the last two years of his contract.
"But if he doesn't get an opportunity at Southampton and it is getting close to transfer deadline day at the end of August, or when the loan window opens back up a couple of weeks after, we will have to start making a decision about what is best for Billy.
"There is no rush at the present though because as I said before there is the loan window, but if he is to go to another Premier League club or another territory then it will have to be done before this current transfer window closes."
Sharp's former club Doncaster had a request to take him on a season-long loan rejected last month, while Forest have also been linked with an approach.
As recently as this morning Sheffield Wednesday boss Dave Jones flat-batted talk of a move for the ex-Sheffield United favourite, but such a move would mean another season in the Championship.
And, according to Featherstone, Sharp's preference is to remain in the Premier League should he leave Saints, who he believes would be looking to sell the striker rather than send him out on loan again.
"For Billy going to Southampton was his opportunity to play for a Premier League club," said Featherstone.
"While that hasn't happened in terms of getting out on the pitch, now that he has experienced being in the Premier League, if you like, then I certainly think it will form a big part of Billy's decision was he to go elsewhere from Southampton.
"Billy is a good goalscorer and a lot of teams in the Premier League and Championship are short of goals so as you can imagine there have been enquiries.
"I think Southampton are probably holding out to see if there are any more enquiries that come in that are more suitable as at this stage that is not in their interest."