Town are reportedly eyeing Oxford United central midfielder Mark Sykes, while their interest in Dundee United keeper Benjamin Siegrist is said to be facing frustration.
According to The Sun on Sunday, the Blues are interested in signing the 23-year-old Northern Irishman this summer.
Belfast-born Sykes joined Oxford from Glenavon in 2019 in January 2019 and since then has made 66 starts and 26 sub appearances, scoring three times, helping the U's into the League One play-offs in both seasons.
The report claims the Belfast-born schemer is out of contract this summer, however, Oxford triggered a one-year option on his deal at the end of April.
Having been capped 11 times at U21 level by Northern Ireland, scoring twice, Sykes has since switched his international allegiance to the Republic of Ireland but is yet to win a cap although is on standby for their June friendlies against Andorra and Hungary.
Meanwhile, the Blues reported interest in Siegrist is, also according to The Sun on Sunday, being frustrated by the 29-year-old waiting to see whether Celtic firm up their interest.
Siegrist, who is out of contract this summer, has been linked with Celtic, who are currently managerless, since January.