In a fiercely-fought contest at the Riverside Stadium, that saw Neil Warnock's side dominate possession and take ten shots to the visitors' two, Paddy McNair's 82nd minute goal secured a draw for his side and ended the Bluebirds' relentless six-game winning streak.
Speaking after the game, Boro's boss was quizzed on the fitness of his January signings, and he claimed: "He (Nathaniel Mendez-Laing) will get sharper. He has been out a long time really. That’s the same with (Neeskens) Kebano really, he hasn’t had much football.
"Yannick (Bolasie) hasn’t either, and if you had seen him on the training ground yesterday…they told me he wasn’t fit as well.
“I think I am in the wrong game. They say he has to do longer sprints, longer runs. Hopefully he will be available at some stage before next weekend I hope.”
Middlesbrough are back in action tomorrow evening, when they travel to take on Coventry City at St. Andrew's.
Here are today's biggest transfer stories and the latest team news involving Middlesbrough and the rest of the Championship, ahead of the midweek action:
1. Howe favourite for Celtic job
Ex-Bournemouth manager Eddie Howe is the fresh favourite for the Celtic job, as the Scottish Premiership champions eye up Neil Lennon's successor. Howe has been out of work since leaving the Cherries last August. (SkyBet) Photo: CLIVE BRUNSKILL
2. Milan join Aarons chase
AC Milan are the latest side to be linked with a move Norwich City sensation Max Aarons. They join Everton, Man Utd, and current favourites Bayern Munich in the race to sign the £35m-rated full-back. (Football League World) Photo: Stephen Pond
3. Defoe tipped for Championship move
Ex-football Noel Whelan has claimed Rangers' Jermaine Defoe, 38, is still good enough to impress in the Championship, and would be a "massive signing" for any second-tier side able to sign him in the next transfer window. (Football Insider) Photo: Ian MacNicol
4. Warnock spreads net wide in striker search
Middlesbrough boss Neil Warnock has revealed he's determined to sign a new striker this summer, and hinted that he'll be exploring options "on the continent", as he looks to unearth a hidden gem in Europe during the next transfer window. (Hartlepool Mail) Photo: Stu Forster