Reports suggest that the Teessiders, aiming to continue their unbeaten start to the Championship season at home to QPR on Wednesday night - are poised to bring Bidwell to the club, having identified the 28-year-old as their number one target to provide another much-needed option on the left-hand side of their defence.
Warnock said: “Something is close. I'm hoping to put a left-sided player into the squad this week. Will it be done before the end of the week? I hope so, yeah, it will give us some help.
“I’ve got to keep whatever I can about the targets to myself really. I don’t like talking about other players from other clubs.
“Jake’s a good player, but there’s so many others that we’re looking at as well in that area. If (Marc) Bola was to get injured at the moment, then we’ve lost all the left-sided lads as back-up. So, we do need somebody in that area."
Boro's other major priority is up front, with Warnock desperate to land a couple of strikers to boost his side's firepower.
A number of forwards have been linked over the summer, including Rotherham United's Michael Smith, with Boro now being heavily linked with a move for Sporting Lisbon frontman Andraz Sporar.
The Slovenian international, 27, spent the second half of last season at Braga, with Sporting willing to do business and sell the player if the right offer comes in.
So far in the current window, Boro have boosted their attacking options with the addition of Uche Ikpeazu and Matt Crooks - who both scored in the weekend win over Bristol City - and Sammy Ameobi, who is currently sidelined.
Argentine midfielder Martin Payero has also arrived alongside keepers Joe Lumley and Luke Daniels and veteran defenders Sol Bamba and Lee Peltier.