Ulster assistant coach Allen Clarke told BBC Sport Northern Ireland the club is aware that Tuohy "is in communication with other options".
"That is going through due process at the moment. It would probably be inaccurate for me to speculate any further," added Clarke.
Tuohy, 31, has played 136 times for Ulster and earned 11 Ireland caps.
The Bristol-born lock was already Irish-qualified when he joined Ulster from Exeter in 2009 and made his Ireland Test debut a year later against the All Blacks.
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He starred against Scotland in the 2014 Six Nations when replacing injured Paul O'Connell but then suffered a broken arm in the next game against Wales.
Tuohy fractured an ankle last December and only returned to action last month.
After playing for Ulster A in late October, he started in both the Pro12 defeats by Munster and Edinburgh.
His last Ireland game came in the World Cup warm-up encounter with Scotland in August 2015 as he missed out on a place in the squad for the tournament which started a month later.
Tuohy then looked a strong contender to replace Paul O'Connell after the captain was injured in the win over France at the World Cup but coach Joe Schmidt instead called up Leinster's Mike McCarthy.
"He has been fantastic for us but has had a frustrating couple of years because of injury," added Clarke.
"I remember him as a young man arriving and what he has developed into - that experience is precious.
"But if he is to move on, it opens up an avenue for someone else and we've got some good young locks in Ulster."
Ireland second row Dan Tuohy is set to move from Ulster to his hometown club Bristol before Christmas.